aircall_send_message

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

Annotations already indicate a non-read-only, non-destructive operation. The description adds value by noting the direct-send behavior (bypassing the Inbox) and the messaging configuration requirement, but it does not disclose other behavioral aspects such as side effects (e.g., costs, delivery guarantees) or return value structure.

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 two sentences with no redundant information. It front-loads the main action and immediately provides a key distinction (bypassing the Inbox) and a prerequisite.

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?

There is no output schema, and the description does not explain what the tool returns (e.g., success status, message ID). It also omits potential side effects. However, it does cover the essential usage context and prerequisite, making it adequate but not fully complete.

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 input schema has 100% description coverage for all four parameters, including the requirement that number_id must have messaging enabled. The description itself adds no parameter-specific details, 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?

Description clearly states the action ('Send an SMS/MMS') and the resource ('from an Aircall number'). It adds the qualifier 'bypassing the Aircall Inbox,' which helps distinguish it from sending through the inbox, though it does not explicitly name alternative sibling tools like aircall_send_agent_message.

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 context for when to use this tool ('bypassing the Aircall Inbox') and a prerequisite ('The number must have messaging configured'), but it does not explicitly state when not to use it or name alternatives. The usage guidance is implied rather than explicit.

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