aircall_start_call

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

Annotations indicate non-read-only and non-destructive, which align with the description. The description adds valuable context by disclosing that the user's phone rings first before connecting to the destination, going beyond the annotations.

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?

Two concise sentences that immediately state the primary purpose and follow with a crucial behavior detail. No filler or redundant information; every sentence earns its place.

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 three-parameter tool with existing schema and annotations, the description provides adequate context for call initiation. While it could mention return values or prerequisites, the core flow is sufficiently covered.

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?

Input schema descriptions fully cover all three parameters with clear meanings, achieving 100% schema coverage. The description does not add extra parameter semantics beyond the phrase 'on behalf of a user,' which is supported by the schema's user_id description.

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 action ('initiate an outbound call') and the actor ('on behalf of a user'), with a specific behavioral detail (ring first, then connect). This distinguishes it from sibling tools like aircall_dial by emphasizing the user's phone ring sequence.

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?

Provides implied usage context ('on behalf of a user') but does not explicitly state when to use this tool versus alternatives such as aircall_dial or aircall_trigger_agent_call. No exclusions or alternative tool mentions are present.

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