Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare idempotentHint=true and destructiveHint=false. The description adds valuable context: it writes vdd/impact-report.generated.md, never overwrites a hand-authored vdd/impact-report.md, and explains artifactFiles behavior for serverless runs. It does not specify what happens when a hand-authored report exists (skip vs error), but the disclosure is still strong.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three dense sentences with no filler: scope, file behavior, usage timing, sibling alternatives, and the artifactFiles caveat are all covered efficiently. The most important information is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a complex 10-parameter tool with no output schema, the description covers purpose, timing, alternatives, file output, and a special parameter. Minor gaps remain around return/result behavior and what happens when the hand-authored report exists, but overall it is nearly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds meaningful clarification for artifactFiles, explaining it maps artifact path to content for serverless runs and should be omitted locally. Other parameters are adequately documented in the schema itself.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ('Validate') and resource ('the full chain'), then enumerates the concrete checks: traceability matrix, drift detection, orphan detection, uncovered vision goals, impact metrics vs targets, and 28 S&T assumption checks. It also explicitly distinguishes itself from vdd_analyze and vdd_trace, so an agent can tell which tool to use.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly says 'Run after implementation is complete' and names alternatives with their conditions: use vdd_analyze for a lightweight per-feature consistency check and vdd_trace for the matrix alone. This gives clear when-to-use and when-not-to-use guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.