Agent Skills: Validate Plan

Validate Plan

Validate that an implementation plan was correctly executed by comparing the plan's claims against the actual codebase state.

Input

• If a plan path is provided, use it
• Otherwise, search thoughts/shared/plans/ or ask the user

Validation Steps

1. Read the plan completely — identify every phase, checkbox, success criterion, and manual verification item.

2. Read every file the plan references — source code, test files, config files. Compare what the plan says should exist against what actually exists.

3. Run automated verification — execute make test (or whatever the plan specifies). Capture full output.

4. Compare plan claims to reality for each phase:

   • Do checked items ([x]) match what's actually in the code?
   • Do function names, signatures, and behavior match what the plan specifies?
   • Are there deviations (renamed functions, changed parameters, extra code not in plan)?
   • Are there items marked complete that are missing or incomplete?

5. Assess test quality — don't just check that tests pass. Read the test code:

   • Do tests actually assert the expected behavior, or are assertions missing/trivial?
   • Do tests mock the method they're supposed to test (tautological tests)?
   • Do the plan's success criteria have corresponding test assertions?

6. Look for regressions — did the implementation break pre-existing methods or behavior? Check methods that aren't part of the plan but exist in modified files.

7. Evaluate plan quality — if the plan has vague or unmeasurable criteria ("handle edge cases well", "good performance"), flag them as unverifiable rather than inventing interpretations.

Report Format

## Validation Report: [Plan Name]

### Implementation Status
Phase N: [Name] — [Fully implemented | Deviations found | NOT implemented]

### Automated Verification
[Full test output, pass/fail count]

### Findings
[What matches the plan, what deviates, what's missing, what's broken]

### Recommendations
[What needs fixing before this can be considered complete]

Key Principles

• A passing test suite does not mean the plan is satisfied — tests can lie.
• Checked checkboxes do not mean work is done — verify against actual code.
• "It works" is not the same as "it matches the plan" — semantic mismatches matter.
• Vague criteria cannot be validated — flag them, don't rubber-stamp them.