End a call

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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=true, and openWorldHint=true. The description adds some behavioral nuance (polite wrap-up, handling unconnected calls) but does not detail what gets destroyed, auth needs, or rate limits. With annotations covering the safety profile, a 3 is appropriate.

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?

A single, front-loaded sentence with no wasted words. It efficiently conveys the two use cases. 5.

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?

Given the simple one-parameter tool, rich annotations, and no output schema, the description covers purpose and usage adequately. Minor gaps (e.g., what happens if the call already ended) are not critical. 4.

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 coverage is 100% for the single callId parameter, and the schema itself describes it as 'Call id returned by start_call'. The description does not add any parameter meaning or format details. Baseline 3.

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: 'Ask the assistant to wrap up politely and hang up, or cancel a call that has not connected yet' – clear verb+resource. It does not name any sibling tool for differentiation, so it fits a 4.

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?

It gives clear context for when to use: wrapping up an active call politely or cancelling an unconnected call. It does not mention alternatives like transfer_call_to_me or send_call_instruction, nor any when-not conditions, so 4.

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