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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behaviour beyond that: missing facts are surfaced as [square-bracket] gaps rather than invented, and the exact return payload (letter, last day, checklist with three named checks) is stated. No auth or rate-limit notes, but none appear relevant.

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?

Three short sentences: purpose and derived output first, then the gap-filling convention, then the return contract. No filler, no restatement of the title, and the most decision-relevant clause is front-loaded.

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 12-parameter, zero-required, no-output-schema tool, the description covers what it produces (letter, last day, checklist) and how gaps are handled. The only real omission is guidance on when this tool should not be used, which leaves a small hole in an otherwise complete definition.

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 every one of the 12 parameters is already documented with defaults, enums and formats. The description adds only the causal link that notice drives the computed last working day, which is marginal. Baseline 3 is appropriate when the schema does the heavy lifting.

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?

The description names a specific verb and resource ('Draft a ... resignation letter') plus a secondary capability ('work out the last working day from the notice period'). This is instantly distinguishable from draft_cover_letter, tailor_resume, and the other career siblings, none of which touch resignation content.

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?

Usage is only implied: an agent can infer this is for someone leaving a job, but no explicit when-to-use, when-not-to-use, or alternative tool is named (e.g., no pointer for counter-offer or notice-negotiation cases). The notice vs. notice_days routing advice is parameter-level guidance rather than tool-selection guidance.

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