aircall_get_user_numbers

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

Annotations already declare readOnlyHint=true, so the description does not need to restate safety. It adds useful context by specifying 'all phone numbers' and 'API v2', which clarifies scope and versioning. No behavioral contradictions exist.

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 a single concise sentence that front-loads the action and resource. Every word contributes meaning, with no redundant filler or repetition of the tool name.

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?

With a single required parameter and read-only annotation, the description fully covers the tool's purpose and scope. There is no output schema, but the description's mention of 'all phone numbers' implies the return type sufficiently for a simple getter. No additional context is needed.

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?

The schema has 100% coverage with a description for user_id ('The user ID'). The tool description adds no additional parameter semantics beyond what the schema already provides, so the baseline score of 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?

The description 'Get all phone numbers assigned to a specific user' uses a specific verb ('Get') with a clear resource ('phone numbers assigned to a specific user') and scope ('specific user'). This distinguishes it from sibling tools like aircall_list_numbers (all numbers) or aircall_get_number (a single number).

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 when you have a user_id and need their assigned phone numbers, but it does not explicitly state when to use it over alternatives. It does not mention alternatives or exclusions, so it relies on the user to infer the appropriate context.

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