List Person Phone Numbers

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds useful context beyond annotations: it specifies the return format options (markdown/json), details the error response ('Error: Resource not found'), and lists what data is returned (carrier, location, primary status). However, it doesn't mention rate limits, authentication needs, or pagination behavior.

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 well-structured and front-loaded, starting with the core purpose, followed by Args and Returns sections. Every sentence earns its place: the first sentence states the purpose, the Args clarify parameters, and the Returns/Error sections provide essential output details without redundancy.

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?

Given the tool's low complexity (2 parameters, no nested objects), rich annotations (covering safety and idempotency), and no output schema, the description is mostly complete. It explains the purpose, parameters, return data, and error handling. However, it could improve by mentioning authentication requirements or rate limits, which are not covered by annotations.

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%, with both parameters fully documented in the schema (person_id as 'The PCO person ID' and response_format with enum and default). The description adds minimal value beyond the schema, only restating the default for response_format and implying person_id is required. Baseline 3 is appropriate since 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 clearly states the verb ('Get all phone numbers') and resource ('for a specific person in PCO'), making the purpose specific. It distinguishes from sibling tools like pco_get_person (which retrieves general person data) and pco_list_people (which lists multiple people), focusing exclusively on phone numbers for a single person.

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 provides clear context by specifying it's for 'a specific person' and mentions error handling for invalid IDs, which helps guide usage. However, it doesn't explicitly state when to use this tool versus alternatives like pco_get_person (which might include phone numbers) or pco_list_person_emails, missing explicit sibling differentiation.

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