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

Annotations already declare readOnlyHint and non-destructive behavior. The description adds valuable context: uses 'Loa heuristics plus AI', is 'not authoritative or diagnostic', and requires an account. 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 concise sentences: purpose, usage guidelines, and requirement. Front-loaded with main function, zero superfluous words.

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?

Despite having an output schema, the description covers all needed context: when to use, how to follow up, non-authoritative nature, and account requirement. No gaps for such a simple 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?

Only one parameter (query) with 100% schema coverage, including an example in the description. The description adds a plain-English interpretation and example, slightly enhancing the schema's definition.

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 it suggests CPT codes from plain-English medical needs, using 'suggests likely CPT codes' as the verb-resource pair. It distinguishes from siblings like search_cpt_codes by specifying the use case.

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?

Explicitly states when to use ('only when the user cannot name the procedure'), what to do after ('confirm candidates with search_cpt_codes before pricing'), and a prerequisite ('Requires a LOA account'). This provides clear decision-making criteria.

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