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

Annotations already cover readOnly/idempotent/non-destructive, but the description adds substantial behavioral context: matching ignores case/punctuation/common words, it does not validate new claims, no-match is not a negative verdict, and it returns up to 20 results. These are non-obvious traits an agent needs for correct interpretation.

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?

Front-loads purpose and the sibling-routing rule, then parameters, then return shape and caveats. Every sentence carries distinct information; no filler despite the length.

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 adequately describes the return (route_id, matched wording, scoped question; ~20 matches) and the downstream preview path. It covers purpose, routing, parameters, result shape, and matching caveats for a read-only search tool.

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%, so baseline is 3, but the description adds useful semantics beyond the schema: 160-character max on query, offset maximum 10000 with a +20 page-increment convention, and the browse behavior when query is blank. It reinforces rather than merely restates.

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 ('Search existing reviewed evidence questions and fixed-pack topics') with clear scope ('when you do not know a route ID'). Explicitly names the sibling tool find_package_advisories for the contrasting case, so an agent can pick correctly without opening schemas.

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?

Gives explicit when-to-use (governance, tool permissions, audit/export, evidence-boundary questions; unknown route ID), when-not ('For a known software advisory ID or an exact ecosystem/package lookup, use find_package_advisories'), and a downstream step (pass route_id to preview_evidence_answer). Nothing is left to inference.

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