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

Annotations already declare readOnlyHint and idempotentHint; the description reinforces this with 'Read-only; returns metrics without modifying files' and adds the specific metrics it checks. No contradictions. It adds context about what gets analyzed but doesn't cover edge cases or output structure; however, annotations lower the bar, and this is sufficient.

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?

The description is dense but every sentence contributes: purpose, checks performed, read-only guarantee, parameter instruction, and usage guidance with alternatives. It is front-loaded with the core purpose and efficiently structured, with no filler.

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 read-only analysis tool with no output schema, the description covers the main function, inputs, and usage context. It doesn't specify the exact metrics output format, but that's arguably acceptable given the tool's simplicity and the annotations covering safety. The main gap is that it doesn't address why the other 9 parameters exist, but the schema covers them, so completeness is adequate.

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 coverage is 100% for all 10 parameters, so the baseline is 3. The description adds a meaningful clarification by stating 'Pass feature (the spec directory name)', which directly maps to the primary parameter and disambiguates its role. It does not explain other parameters but the schema already does; the added focus on 'feature' lifts it to a 4.

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?

The description clearly states the tool performs cross-artifact consistency analysis for a single feature, enumerating specific checks (AC count, unresolved markers, placeholder density, file existence). It explicitly differentiates from sibling tools by naming vdd_trace (project-wide matrix) and vdd_validate (release validation), so an agent can select the right tool without ambiguity.

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?

The description provides explicit when-to-use guidance ('Use during planning and implementation to check a spec is complete') and when-not-to-use with direct alternatives ('for the project-wide matrix use vdd_trace, and for release validation use vdd_validate'). This fully answers the selection question.

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