Record an Android display

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

Discloses blocking behavior and bounded duration, which are not captured by annotations. No contradiction with annotations (readOnlyHint=false, openWorldHint=true, etc.).

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?

Two concise sentences, front-loaded with core action, no wasted 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?

Given the tool's simplicity and presence of output schema, the description covers essential points: blocking, bounded duration, and alternative tool. Could mention output details but not critical.

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 covers 67% of parameters (serial and displayId have descriptions). Description implies duration parameter via 'bounded duration' but adds no new details beyond schema for serial/displayId. DurationSeconds lacks description in schema and description.

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?

Clearly states it records a display with 'Blocking record of one physical-backed display for a bounded duration.' Distinguishes from sibling tools by explicitly preferring mobile_record_start/mark/stop for interleaved input.

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?

Provides explicit alternative for a specific use case ('when input must be interleaved'), guiding when not to use this tool. Could be improved by mentioning other relevant sibling tools.

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