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

Beyond the annotations (readOnly, non-idempotent, non-destructive, closed-world), the description discloses that part of the answer is AI-drafted (Gemma 4 with Llama 3.3 70B fallback on Cloudflare Workers AI), that a guard drops any figure/name/tool not in the user's text, and that the rule-based portion still returns with ai.message explaining failure. This is rich disclosure of non-obvious runtime behavior that explains the non-idempotency.

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?

Purpose and scope are front-loaded in the opening clause, and the sentences carry substantive information. It is dense and slightly overstuffed with model/carrier detail, but each clause maps to real behavior rather than 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?

With no output schema, the description usefully sketches the return shape (missing keywords, suggested rewrites, borrowed-terms list, confirm_with_user list, ai.message) and the degradation path. It stops short of fully specifying the response structure, but is complete enough for an agent to invoke correctly for a two-param 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 description coverage is 100% for both parameters, so the schema already documents plain-text format and length limits. The description adds no syntax or format detail for resume_text or job_description beyond what the schema provides, which is the baseline-3 case.

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 ('Tailor a resume to a job posting') and immediately differentiates the output from siblings by noting the missing keywords come 'from match_job's rules' and the rewrites touch only 'the user's own summary and bullets'. An agent can distinguish it from match_job, improve_bullet, and write_summary 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?

The reference to match_job's rules establishes the workflow context in which this tool is used, and the note that confirm_with_user terms are 'never to add unasked' frames correct invocation. However, there is no explicit when-to-use/when-not-to-use statement or named alternative for the tailoring task itself.

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