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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds genuine value beyond that: it discloses the return shape (match categories exact/normalized/alias/stem, matched spans, source sentences for misses, term weights, required vs preferred, and coverage aggregates) and pins a rules version, which tells the agent results are deterministic and versioned.

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?

A single dense sentence, but it is front-loaded with the action and every clause carries a distinct output fact that has nowhere else to live given the absence of an output schema. Nothing is repeated or decorative.

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 properly absorbs the burden of explaining returns and does so comprehensively, and input constraints are enforced by the schema. The remaining gap is workflow context — it never says how it relates to fetch_job_post, keyword_scan or tailor_resume in a larger pipeline.

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 both parameters are already documented, and the description's '120–20,000 characters' simply restates the schema's minLength/maxLength. It adds no syntax, format or interaction detail beyond the schema, so the baseline 3 applies.

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 pair ('Compare a resume with a job posting') and enumerates exactly what the comparison yields (matched/missing keywords, match type, weights, coverage). It does not, however, distinguish itself from plausible near-duplicate siblings such as keyword_scan or tailor_resume, so an agent cannot tell from the description alone which to pick.

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?

There is no when-to-use or when-not-to-use guidance and no mention of alternatives, even though keyword_scan and check_resume sit in the same sibling set. The only usable precondition ('Posting 120–20,000 characters') is a constraint, not a usage rule, and the 'call fetch_job_post first' advice lives in the schema rather than the description.

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