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

Annotations only declare safety flags (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description adds real value: it discloses the prerequisite ('Requires a connected GetMattered account'), a cost signal ('Uses the user's AI credits'), and the return payload. It does not say whether the rewrite is persisted to the account or overwrites the stored resume, which is the one behavior an agent might still need.

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-loaded with purpose, then returns, then usage branching, then parameter caveats — good ordering. It loses a point for restating the resume_file attachment guidance that already appears verbatim in the schema description, and for telling the agent what the tool returns when an output schema exists.

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 3-parameter, all-optional tool with nested file input and an output schema, the description covers auth, credits, sibling exclusions, parameter precedence, and tailoring behavior. Return values needn't be explained given the output schema, so nothing material is missing for correct invocation.

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 3 is the baseline, but the description adds genuine semantics the schema lacks: job_description changes the output's tailoring rather than just being optional data, and resume_text/resume_file have a defined precedence against the account-stored resume. The file-side details (PDF/DOCX, 10 MB, downloaded once) are already in the schema description and are repeated here.

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 and resource ('Rewrite a resume') plus the objective ('passes ATS screening'), and explicitly separates itself from getmattered_apply. An agent can distinguish this from siblings like getmattered_score_resume or getmattered_translate_resume without opening any schema.

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 an explicit branching rule for job_description ('pass ... or omit it for general ATS optimization') and a hard exclusion ('Do not use it to apply: getmattered_apply ...'). It also spells out the resume_text vs. resume_file vs. account-stored-resume precedence, which is the main invocation ambiguity for this tool.

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