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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context beyond annotations: no auth required, US National Library of Medicine public domain, unlimited free access, and the output limit of 10 results. It does not contradict the 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?

The description is compact and front-loaded with the core purpose. It efficiently combines function, use cases, concrete examples, and access constraints in three sentences without fluff. Every sentence contributes value, and there is no redundancy with the schema.

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 simple 2-parameter tool with a full output schema present, the description covers essential context: what it does, how to use it, example inputs, and access characteristics. It does not need to describe return values since the output schema existshome. Nothing an agent needs to invoke 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 description coverage is 100%, so the schema already documents both parameters with examples. The description reinforces the example inputs ('dia', 'hyp', 'pneu') and mentions the max_results range implicitly via 'up to 10', but does not add meaning beyond the schema. Baseline 3 is appropriate.

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 clearly states the action ('Get fast ICD-11 code autocomplete suggestions'), the resource ('partial clinical term'), and the output ('up to 10 matching codes and titles'). It distinguishes itself from siblings like 'search' and 'lookup' through the autocomplete context and 'as the user types' phrasing, so an agent can differentiate without opening schemas.

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 implies usage through examples ('Input partial terms like "dia"...') and specific use cases ('building clinical coding interfaces, EHR integrations'), but it does not explicitly mention when to use this tool versus siblings or state exclusions. There is no 'use search instead' guidance, so it falls short of clear when/when-not guidance.

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