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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), but the description adds real value: it discloses the return format (plain text letter with [brackets] placeholders, an attachment checklist, tips) and the key operational boundary that it 'never sends or files anything.' These are behaviors not visible in annotations or schema.

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 triggering examples, then output/behavior. Four sentences, each carrying information, with no boilerplate. Slightly dense in the middle but nothing is wasted.

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 14-parameter, all-optional drafting tool with no output schema, the description covers what the tool produces and that it does not send anything. It does not explain how placeholder substitution or checklist generation works, but nothing an agent needs to call it correctly is missing.

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% across 14 properties, so the schema already documents every parameter, including enums and the reason/denial_code fallback. The description adds only the implicit note that unfilled fields become [brackets] placeholders, which is marginal beyond what the schema states. 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 and artifact ('Draft an appeal letter') and adds scope in the title ('for the user to review and send'). This clearly separates it from siblings like get_appeal_deadlines or explain_denial_code, which inform rather than produce a document.

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 two concrete triggering utterances ('my insurer denied my MRI as not medically necessary' and 'write an appeal letter for an out-of-network denial'), which tells the agent when to pick this tool. It does not explicitly name alternative siblings or state when not to use it, so it falls short of a 5.

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