Stop Screen Recording

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

The description adds meaningful behavioral information beyond the annotations: it discloses the return values (file path, size, approximate duration). readOnlyHint=false is consistent with a state-changing stop action, and the description further clarifies that the result is a saved recording artifact rather than merely a confirmation.

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 one efficient sentence that front-loads the core action and then lists the key outputs. There is no filler or redundant restating of the title.

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 one-parameter tool, the description covers the action, the precondition ('active'), and the return values. It could mention failure behavior when no recording is active, but this is a minor gap given the simplicity and clarity of the overall definition.

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 description coverage is 100% for the single device parameter, and the schema already provides helpful guidance on discovering available devices via mobile_list_available_devices. The tool description does not add additional parameter semantics, so the baseline 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?

The description clearly states the action ('Stop'), the target resource ('an active screen recording on a mobile device'), and the expected output. It distinguishes itself from the sibling mobile_start_screen_recording by saying 'Stop' and 'active'.

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 tells the agent this is for ending a currently active screen recording, which makes the usage context clear. It does not explicitly mention that a recording must have been started first, but 'active' implies that precondition strongly enough.

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