aircall_update_phone

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

Annotations already indicate destructiveHint=true and readOnlyHint=false, signaling a mutating operation. The description adds no extra behavioral context beyond 'update': it doesn't clarify whether both label and value can be updated together, whether it's a partial update if only one field is provided, or what happens if the phone_id doesn't belong to the contact. Since the description overlaps with annotations without adding value, the score is low.

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, short sentence that immediately conveys the tool's purpose. There is no redundant or filler content; every word contributes meaning. This is an example of ideal conciseness.

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 seemingly simple update tool with 4 parameters, 2 required, and a clear schema, the description is minimally viable. However, it lacks mention of partial-update semantics (only label or only value), potential failure modes, or guidance for distinguishing from aircall_update_number other than 'on a contact.' While annotations and schema cover some details, the description could be more complete for correct invocation.

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 each parameter (label, value, phone_id, contact_id) already documented in the input schema. The description does not add any parameter-specific details beyond stating that it updates a phone number, which is consistent with the schema. With full schema coverage, the baseline of 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 'Update a phone number on a contact' clearly states the specific action (update) and resource (phone number on a contact), which distinguishes it from sibling tools like aircall_add_phone and aircall_delete_phone. The phrase 'on a contact' differentiates it from aircall_update_number, which likely updates a phone number at the company level.

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 when to use the tool—when you need to modify an existing phone number associated with a contact—but provides no explicit guidance on when to use alternatives like add_phone for new numbers or delete_phone for removal. No prerequisites (e.g., contact and phone must exist) or exclusions are mentioned.

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