start_recording

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits, but it only mentions the output format and optional restrictions. It fails to disclose that recording continues until stopped, potential permission prompts, or asynchronous behavior, which are critical operational side effects.

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, well-structured sentence that front-loads the verb and resource, includes the key output format, and has zero filler. It achieves maximum clarity in minimal words.

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?

The description covers the basic purpose and optional parameters, but it lacks essential workflow context such as the need to stop recording with a sibling tool, how the recording is finalized, or what the call returns. Given the tool's moderate complexity and absence of an output schema, this is a noticeable gap.

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 description summarizes the display and area parameters as 'Optionally restrict to a display number or a pixel region,' but the input schema already provides detailed descriptions for all parameters, including nested area properties and output default. The incremental semantic value is limited, so the baseline score of 3 for high schema coverage is appropriate.

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 ('Start recording the screen'), specifies the output format (.mov) and platform (macOS native screencapture), and distinguishes itself from sibling tools like stop_recording and recording_status by focusing on the initiation of recording.

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?

No explicit guidance is provided on when to use this tool versus alternatives. While sibling names imply a paired workflow with stop_recording, the description does not state prerequisites, exclusions, or recommend alternative tools for specific scenarios, leaving the agent without selection context.

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