Agent Skills: Evaluate FiftyOne Plugins

Evaluate FiftyOne Plugins

Key Directives

ALWAYS follow these rules:

1. Read the entire plugin before judging

Read every source and configuration file of the plugin. Common file extensions: .py, .ts, .tsx, .js, .yaml, .yml, and .json. Never construct an assessment of a plugin without first reading every line of every source file.

2. Security first

Check for dangerous patterns before anything else. A plugin with perfect code quality that violates established and well known security best practices, is an immediate critical failure.

3. Be specific and actionable

Every finding must include: what's wrong, where it is (file + line), why it matters, and how to fix it. Never say "improve code quality" without pointing to the exact issue.

4. Score honestly

A plugin by a trusted org with security issues still gets a security failure. A community plugin with great code still gets credit. Judge the code, not the author.

5. Check the real plugin framework

Always verify the plugin under assessment against the actual FiftyOne plugin system. Use MCP tools to list operators, get schemas, and check registration — don't just read files.

list_plugins(enabled=True)
list_operators(builtin_only=False)
get_operator_schema(operator_uri="@org/operator-name")

Evaluation Workflow

Phase 1: Manifest & Structure

Check the plugin is well-formed before loading it.

1.1 Parse fiftyone.yml:

• name exists and follows convention (@org/plugin-name)
• version is present and valid semver
• fiftyone.version constraint is specified
• operators and/or panels lists are non-empty
• secrets are declared if the plugin uses API keys

1.2 Skills declaration:

• Check if fiftyone.yml includes a skills: section listing companion skills (similar to operators: and panels:)
• If skills: is declared, verify each listed skill has a matching SKILL.md file in the plugin directory following the Agent Skills format (YAML frontmatter with name and description, plus workflow sections)
• If no skills: section exists, note this as an observation — the plugin does not ship with companion skills for AI assistants. This is not a penalty, but plugins with skills have higher agent success rates.

1.3 File structure:

• __init__.py exists
• Every operator in manifest has a matching class in the Python entry file
• Every panel in manifest has a matching class
• If panels declare: dist/index.umd.js exists (built JS bundle)
• requirements.txt exists if the plugin imports third-party packages (anything not in Python's standard library, packages that require pip install)

1.3 Dependencies:

• All Python imports resolve (importlib.util.find_spec)
• No pinned versions that conflict with FiftyOne's dependencies

Fail criteria: Missing fiftyone.yml, missing name, or entry file doesn't exist → stop eval, report as broken.

Phase 2: Security & Trust

This is the most critical phase. FiftyOne plugins run with full OS-level permissions — no sandbox. A plugin can read files, make network calls, run commands, and access environment variables. Check for misuse.

2.1 Filesystem access — scan all Python files for:

# CRITICAL: Look for these patterns
open()           # File read/write — is it within the plugin directory or dataset paths?
os.path          # Path manipulation — is it accessing user home, SSH keys, credentials?
shutil           # File copying — where is it copying to?
pathlib          # Same as os.path
glob.glob        # File discovery — what directories is it scanning?

Acceptable: Reading/writing within FiftyOne dataset directories, plugin directory, temp files. Suspicious: Reading ~/.ssh/, ~/.aws/, ~/.config/, /etc/, or any path outside FiftyOne scope. On Windows, equivalent suspicious paths are %USERPROFILE%\.ssh\, %USERPROFILE%\.aws\, %APPDATA%\, and C:\Windows\System32\. Credential access must go through the fiftyone.yml secrets: mechanism (see 2.4) — direct filesystem reads of credential files bypass the user consent contract even if the secret is declared in the manifest. Critical: Writing to system directories or reading credential files. Plugin properly leverages and handles environment variables

2.2 Network access — scan for:

# CRITICAL: Look for these patterns
requests         # HTTP calls — to where?
urllib           # Same
http.client      # Same
socket           # Raw sockets — almost never legitimate for a plugin
aiohttp          # Async HTTP
httpx            # Same

Acceptable: Calls to documented APIs and services the plugin integrates with (e.g., annotation backend, model API) that match declared secrets. Suspicious: Calls to unknown external endpoints, IP addresses, or domains not directly related to the plugin's stated purpose or related services. Critical: Data being sent to external servers that includes dataset content, user info, or environment variables.

2.3 Command execution — scan for:

# CRITICAL: These should rarely appear in plugins
subprocess       # Shell commands — what commands?
os.system        # Same
os.popen         # Same
exec()           # Dynamic code execution
eval()           # Same
__import__       # Dynamic imports
importlib        # Another pattern for dynamic imports

Acceptable: Running specific, documented external tools (e.g., ffmpeg for video processing in an I/O plugin). Suspicious: Running arbitrary shell commands, especially quietly or in an obfuscated manner, with user-provided input. Critical: exec() or eval() on any string, bytes, or arbitrary code not directly included in plaintext with the plugin.

2.4 Environment variable access:

# Check for broad env var access
os.environ       # Reading ALL env vars — plugins should only use declared secrets
os.getenv        # Reading specific env vars — which ones?

Acceptable: Reading env vars that match the plugin's declared secrets in fiftyone.yml. This is the only legitimate credential access path — even if a secret is declared, reading the same credential from disk (e.g., ~/.aws/) is still suspicious (see 2.1). Suspicious: Reading env vars not declared as secrets (e.g., AWS_SECRET_ACCESS_KEY, GITHUB_TOKEN). Critical: Iterating over os.environ to dump all environment variables or sending environment variable contents to locations not related to service authentication.

2.5 Data exfiltration patterns — check for combinations:

• Reads a file + makes a network call in the same function → suspicious
• Reads env vars + makes a network call → suspicious
• Accesses dataset samples and/or writes to a non-FiftyOne path → suspicious
• Patterns allowing arbitrary path traversal or relative path access
• Base64 encoding + network call → highly suspicious

2.6 Dependency supply chain:

• Check requirements.txt for known malicious packages
• Check for typos (e.g., reqeusts instead of requests)
• Flag packages with very low download counts or no source repository

Fail criteria: Any critical finding in 2.1–2.5 → plugin is unsafe, stop eval and report immediately.

Phase 3: Registration & MCP Readiness

Load the plugin and verify it integrates correctly with FiftyOne.

3.1 Registration:

list_plugins(enabled=True)  # Plugin appears?
list_operators()            # All declared operators visible?

• register() function completes without errors
• All operators from manifest appear in registry
• No name collisions with builtin @voxel51/* operators

3.2 MCP tool exposure: (Optional)

• Operators that should be LLM-accessible are exposed as MCP tools
• Internal/helper operators are correctly marked as unlisted=True
• Each exposed tool has a description that would help an LLM choose it

3.3 Startup behavior:

• If any operator has on_startup=True, verify it executes cleanly
• Startup operators should be fast (< 1 second) — they block App initialization
• Side effects must be limited to lightweight initialization (loading config, registering state) — no data mutations, network calls, or heavy computation at startup

Phase 4: Schema & Contract Quality

Check that every operator has well-defined inputs and outputs.

4.1 Input schemas:

# For each public operator
get_operator_schema(operator_uri="@org/operator-name")

• resolve_input() returns a valid property tree
• Required fields are marked as required=True
• Fields have descriptive labels (not "field1", "param_a")
• Enums have reasonable option lists
• Dynamic operators (dynamic=True) adapt their schemas correctly

4.2 Output schemas:

• resolve_output() exists for operators that return meaningful data
• Output types match what execute() actually returns — where type annotations are absent, check that fields declared in resolve_output() are referenced in execute() and vice versa (flag mismatches as warnings, not failures)

4.3 Error handling:

• Empty params → clean validation error, not a crash
• Required parameters that are empty → clean validation error with a clear message shown to the user, no crash or unhandled exception
• Wrong types (TypeError) or invalid values (ValueError) → clean error message shown to the user, no unhandled exception
• Missing required fields → clear indication of what's missing

Phase 5: Risk Classification

Check that operators are correctly classified by danger level.

5.1 Operator severity declaration:

• Check if operators declare a severity in their OperatorConfig (e.g., foo.OperatorConfig(..., severity=foo.Severity.DANGEROUS))
• FiftyOne supports severity levels that control how operators are presented and confirmed in the App
• If no severity is set on any operator, note this as an observation — the plugin does not use the built-in severity system. This means the App won't show automatic risk indicators or confirmation prompts based on severity.

5.2 Destructive operations:

• Any operator that deletes samples, fields, datasets, or files should have allow_delegated_execution=True or require confirmation
• Check for: dataset.delete_samples(), dataset.delete_field(), sample.delete(), shutil.rmtree(), os.remove()
• Destructive operations MUST NOT be auto-executable without user confirmation

5.2 Data modification:

• Operators that modify sample fields, add labels, or change metadata should be clearly labeled
• Users must be notified of all expected changes before execution

5.3 External side effects:

• Operators that make API calls, send data externally, or trigger external systems should require explicit user consent
• Check if the operator description warns the user about external calls

5.4 Cost implications:

• Operators that trigger paid API calls (LLM inference, cloud compute) should document expected cost
• allow_delegated_execution should be true for long-running paid operations

Phase 6: Code Quality

Check the plugin follows FiftyOne conventions.

6.1 FiftyOne patterns:

• Uses ctx.target_view() for processing (not raw ctx.dataset)
• Uses ctx.store() with namespaced keys (not generic "data" or "config")
• Operators performing compute-heavy work (model inference, brain ops, bulk field writes) should expose allow_delegated_execution=True so users can opt in — delegation should be available but not forced
• Operators that iterate over dataset samples should use execute_as_generator for memory efficiency and progress reporting
• Progress reporting for long operations

6.2 Code style:

• Optionally follows fiftyone-code-style conventions (imports, naming, aliases) — flag deviations as suggestions, not failures
• No hardcoded dataset names, file paths, or model names
• Dynamic discovery via list_operators(), get_operator_schema() instead of assumptions

6.3 ExecutionStore usage:

• Store keys are scoped (include plugin name and dataset ID)
• TTL set on cached data (not storing forever)
• No reading other plugins' store keys

Phase 7: Agent Discoverability (Optional)

Check that an LLM agent can effectively use this plugin's tools. Flag all findings in this phase as suggestions, not failures — agent discoverability is a quality improvement, not a requirement.

7.1 Tool naming:

• All operator names, that are not unlisted unlisted=True, describe what they do (compute_embeddings, not run_pipeline_v2)
• Names are distinct from builtin operators (no confusion with @voxel51/* tools)

7.2 Tool descriptions:

• Each operator's label and description clearly explain when to use it
• A non-expert reading just the description could decide whether this tool fits their task

7.3 Ambiguity check:

• No two operators in the plugin have overlapping descriptions
• The distinction between similar operators is clear (e.g., "import_images" vs "import_labels")

7.4 Companion skills:

• Check if the plugin declares skills: in fiftyone.yml (verified in Phase 1.2)
• If skills exist, verify each skill provides a clear step-by-step workflow that reference the plugin's operators
• If no skills exist and the plugin has >3 operators that are typically used in sequence, recommend creating one — it would improve agent success rate significantly

Report Format

Generate the report in this structure:

# Plugin Eval Report: {plugin_name}

## Summary
- **Security Gate:** {PASS | WARN | FAIL} — if FAIL, stop here: DO NOT INSTALL
- **Overall Score:** {score}/100 (N/A if Security = FAIL; capped at 70 if Security = WARN)
- **Quality:** {score}/100
- **Agent Readiness:** {score}/100
- **Critical Issues:** {count}
- **Warnings:** {count}

## Security Assessment
{List each finding with severity, file, line, description, and fix}

## Critical Issues
{Findings that must be fixed before the plugin is safe to use}

## Warnings
{Findings that should be fixed but don't block usage}

## Passed Checks
{What the plugin does well — give credit where due}

## Recommendations
{Ordered list: most impactful fix first, with specific instructions}

## Component Scores
| Area | Score (0–100) | Key Finding |
|------|--------------|-------------|
| Manifest & Structure | {score}/100 | {one-line summary} |
| Security & Trust | {score}/100 | {one-line summary} |
| Registration & MCP | {score}/100 | {one-line summary} |
| Schema & Contract | {score}/100 | {one-line summary} |
| Risk Classification | {score}/100 | {one-line summary} |
| Code Quality | {score}/100 | {one-line summary} |
| Agent Discoverability | {score}/100 | {one-line summary} |

Scoring

Security is a hard gate — evaluate before scoring:

• FAIL (1+ critical findings) → stop evaluation, overall score = N/A, verdict = DO NOT INSTALL
• WARN (1+ suspicious findings) → proceed with scoring, cap overall score at 70/100
• PASS (0 critical findings) → proceed with full scoring

Overall = weighted average of remaining components (only if Security = PASS or WARN):

• Schema & Contract: 25% (correctness matters)
• Agent Discoverability: 20% (usability for LLM agents)
• Risk Classification: 20% (user safety)
• Code Quality: 15% (maintainability)
• Registration & MCP: 10% (basic functionality)
• Manifest & Structure: 10% (basic hygiene)

Quick Reference

Common Security Patterns to Flag

| Pattern | Severity | Why | |---------|----------|-----| | os.environ iteration | Critical | Dumps all env vars including secrets | | subprocess + user input | Critical | Command injection risk | | exec() / eval() | Critical | Arbitrary code execution | | requests.post() + dataset data | Critical | Data exfiltration | | open("/etc/...") / open("C:\\Windows\\...") | Critical | System file access | | open("~/.ssh/...") / open("%USERPROFILE%\\.ssh\\...") | Critical | Credential theft | | socket.connect() | Suspicious | Raw network access | | os.getenv("AWS_*") undeclared | Suspicious | Accessing secrets not in manifest | | shutil.copytree() to external path | Suspicious | Data copying | | No resolve_input() | Warning | Unvalidated inputs | | Generic store keys | Warning | Cross-plugin data leaks |

Score Interpretation

| Score | Meaning | |-------|---------| | 90-100 | Production-ready, well-built plugin | | 70-89 | Good plugin with minor improvements needed | | 50-69 | Usable but has significant gaps | | 30-49 | Needs major work before deployment | | 0-29 | Unsafe or fundamentally broken |

Troubleshooting

For general FiftyOne environment issues (database errors, App won't open, missing plugins, MongoDB failures), use the fiftyone-troubleshoot skill — it covers issues outside the scope of plugin evaluation.

Plugin won't load for evaluation:

• Check fiftyone.yml exists and has valid YAML syntax
• Check Python entry file has no import errors
• Try: python -c "import fiftyone; fiftyone.plugins.list_plugins()"

Can't check MCP exposure:

• Verify FiftyOne MCP server is available
• Check: fiftyone-mcp binary exists in PATH

Security scan finds too many false positives:

• Check if flagged patterns are inside test files (tests/ directory) — lower severity
• Check if network calls match declared secrets — likely legitimate
• Use context: an I/O plugin making HTTP calls to a documented API is expected

Resources

• FiftyOne Plugin Development Guide
• Anthropic's Framework for Safe Agents
• FiftyOne Plugins Repository
• fiftyone-develop-plugin skill — for fixing code quality issues
• fiftyone-code-style skill — for fixing style issues