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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantial extra context: small samples are suppressed, sponsorship is flagged, listed integrations are untested, 'docs-reviewed' means documentation-only verification, and CapaLens protocol tests neither test nor certify vendors. This is behavioral disclosure well beyond the structured fields.

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?

Dense and front-loaded: purpose first, then the interest definition, then parameter rules, then caveats. Every sentence carries information, though the telegraphic disclaimers read as fragments stacked together rather than a flowing structure.

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?

With no output schema, the description usefully discloses return content (vendorTestingPolicy) and the testing-certification posture. It covers the schema's conditional constraint and sampling/sponsorship caveats, but leaves the scene and capability filters undefined, which an agent cannot resolve from the schema either.

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 only 17%, so the description must compensate, and it does for the trickiest part: it explains that days/sortBy apply only to the 'interest' metric, matching the conditional allOf/if-else in the schema. It leaves 'scene' and 'capability' unexplained and doesn't clarify the sortBy enum values beyond the schema's own enums.

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+resource ('Read ... rankings') and enumerates the four metric families it serves (rating, popularity, benchmark, interest), then sharply delimits what 'interest' means. It never names or contrasts a sibling (e.g. get_usage_observations, search_software), so an agent must infer the boundary itself.

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?

It tells you which metric accepts which parameters ('It accepts days 7/30 and sortBy; other metrics reject those parameters'), which is genuine guidance for choosing a call shape. However there is no when-to-use-this-vs-alternatives guidance and no named sibling, leaving tool selection to inference.

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