aircall_add_phone

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

Annotations already indicate that this is a write operation (readOnlyHint=false) and not destructive (destructiveHint=false). The description adds no further behavioral context beyond that, such as prerequisites (e.g., contact must exist) or potential failure modes. This is acceptable but not enhanced.

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, front-loaded sentence that conveys the essential action. It is concise, with no filler or redundant information.

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 3-parameter tool with no output schema, the description adequately covers the action. It does not detail return values or error scenarios, but such details are not critical for this simple add operation given the schema and 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 clear descriptions for label, value, and contact_id. The description itself adds no extra semantic information beyond the schema, so it meets the baseline but does not elevate parameter understanding.

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 uses a specific verb ('Add') and a clear resource ('a phone number to an existing contact'), distinguishing it from sibling tools like update_phone and delete_phone. It also clarifies that the target is an existing contact, not a new one, which differentiates it from create_contact.

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 clearly implies when to use the tool: when you want to associate a new phone number with an existing contact. It does not explicitly state exclusions or alternatives, but the context is sufficient for an agent to decide among related tools such as update_phone or add_email.

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