record_screen_start

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

With no annotations the description carries the full burden and delivers real behavioral context: recording runs in the background, screenrecord caps at 180s per segment, and the mp4 is only obtainable via record_screen_stop. It omits permission/root requirements and what happens on repeated starts.

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?

Three short sentences, each earning its place, with the core action front-loaded and parameter notes and lifecycle handoff following in priority order. No filler.

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?

An output schema exists so return values need not be explained, and the description covers the recording lifecycle and two key parameters. It is still thin on the serial/bit_rate parameters and on any preconditions for a device-mutating capture operation.

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 0% for 4 parameters, so the description must compensate. It explains time_limit_s (duration cap, 180s max per segment) and size (format '720x1280' for downscaling), but serial and bit_rate_mbps are left entirely undocumented.

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?

States a specific verb and resource ('Start recording the screen on-device') and names the companion sibling record_screen_stop, so an agent can distinguish it from capture_screen variants and the stop tool without opening a schema.

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?

Makes the usage context explicit: start recording, then call record_screen_stop to finish and pull the mp4. It gives clear positive routing but no when-not-to-use guidance (e.g., versus capture_screen for stills).

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