phone_call

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

No annotations are provided, so the description carries full burden. It explains the actions and the emulator-only restriction, but does not disclose potential side effects, permission requirements, or error states when actions are used out of order. The information is adequate but not rich.

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 three sentences, front-loaded with the main action, and every sentence provides essential information. There is no fluff or redundancy.

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 tool has 3 parameters, no output schema, and no annotations, the description covers the core behavior and the critical emulator-only constraint. It does not explain return values or error handling, but for a simple ADB command tool, this is sufficient. The optional serial parameter is not mentioned, but it is covered by the schema.

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%, baseline 3. The description adds value by explaining the effects of the action parameter ('rings an incoming call' vs 'transition an in-progress call'), which goes beyond the schema's list of options. This enhances understanding for the agent.

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 tool drives an emulated voice call using adb emu gsm, and lists the specific actions (call, accept, cancel, busy, hold) with their effects. It is a unique verb+resource combination that distinguishes itself from siblings like send_sms or cellular.

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 includes explicit usage context: 'Use to test call-interruption behaviour and CALL_PHONE flows. Emulator-only.' This tells the agent when and where to use it. It does not explicitly state when not to use it or name alternatives, but the context is clear enough.

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