End a call in progress

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

Beyond the annotations, the description discloses the billing impact, the return value, and the required authorization scope. It explains that ending the call stops billing and returns the updated call record, which is meaningful behavioral context not present in the structured 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?

The description is short, front-loaded, and every sentence adds value: what the tool does, the billing side effect, the return value, and the required scope. There is no redundant or filler content.

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 single-parameter tool with one required id and an idempotent, non-destructive annotation profile, the description is complete. It covers the action, the response shape, the auth requirement, and the key side effect, so an agent has enough context to select and invoke the tool correctly.

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 fully documents the single `id` parameter with a description and example. The tool description adds no additional parameter-level semantics, so the baseline score of 3 is appropriate given high schema coverage.

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 states a specific action and resource: "Hang up a live call." It clearly distinguishes itself from siblings like delete_call by noting the call is live and that the updated call record is returned, implying the record remains rather than being deleted.

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?

"Hang up a live call" gives clear context for when to use this tool: when a call is currently active and needs to be ended. It does not explicitly name alternative tools or exclusions, but the live-call framing makes the intended usage reasonably clear.

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