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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: the output is ready to paste into an email, a .txt download link is also returned, and the link is valid for one hour. It also states 'Free on every tier', which is a pricing/availability behavior. No contradiction with annotations.

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 sentences, each earning its place: the first explains the output and its contents, the second adds the download link behavior, the third states pricing. Front-loaded with the core purpose. No fluff.

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 single-parameter read-only tool with full schema coverage and no output schema, the description is nearly complete. It explains what the output contains, the format, the download link validity, and pricing. The only minor gap is not describing the exact structure of the returned text or whether the download link is in the response body, but the description says 'the same text also comes back as a .txt download link', which is sufficient for an agent to invoke it correctly.

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 the schema already documents the work_order parameter. The description adds meaning by explaining that the parameter can be either a work order id or a client name when only one job is theirs, which is valuable disambiguation beyond the schema's example. This exceeds the baseline 3.

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 states a specific verb ('Turn a work order into'), a specific resource ('a plain-text completion report'), and enumerates the content (what was done, labour hours, materials, totals, sign-off block). It also distinguishes itself from the sibling completion_report_pdf by explicitly saying 'plain text' and 'ready to paste into an email'.

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 description clearly implies when to use this tool: when you need a plain-text report for email. It doesn't explicitly say 'use completion_report_pdf for PDF', but the sibling list and the phrase 'plain text' make the alternative obvious. It also notes the .txt download link is valid for one hour, which is a usage constraint. Missing an explicit 'when not to use' statement, but the context is clear.

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