screen_record

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

No annotations are provided, so the description carries the full burden. It explains the output format (MP4) and implies duration control, but does not state whether the recording is real-time, if there are limits on duration, or how the file is returned (local path vs. captured). There is no contradiction with annotations because none exist.

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 a single sentence that efficiently conveys the core action and output format. It is front-loaded with the action. However, it could be slightly longer to include basic usage guidance without losing conciseness.

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 provides minimal context beyond the action. It does not explain return values, file location, or recording behavior (e.g., real-time delay, max duration). While the schema describes parameters, the agent may need more behavioral context to 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?

Schema documentation coverage is 100% for the 3 parameters, so the baseline is 3. The description does not add any parameter-specific semantics beyond what the schema already provides. It mentions 'specified duration' but does not clarify details like default value or path auto-generation already in the schema.

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 uses a specific verb ('Record') and resource ('simulator screen'), directly states the output format ('MP4'), and clarifies the action is time-bounded ('for a specified duration'). This clearly distinguishes it from sibling tools like 'screenshot' or 'log_stream'.

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 implies usage for screen recording but does not provide guidance on when to use this tool versus alternatives like 'screenshot' for a single frame or 'log_stream' for video logs. There is no mention of prerequisites (e.g., simulator must be booted) or explicit when-not-to-use scenarios.

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