screen_record_start

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

No annotations are provided, so the description carries the burden. It states the start/stop lifecycle and mentions a duration limit (in the parameter description). However, it does not disclose other behavioral traits like file size, permission needs, or potential conflicts (e.g., restricting other screen operations).

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 two sentences with no unnecessary words. Every sentence adds value: the first states the purpose, the second explains lifecycle. It is front-loaded and efficient.

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 start-variant tool with no output schema, the description is reasonably complete given the simplicity of the action. It covers the core lifecycle (start/stop) and duration constraint. However, it could hint at return status (e.g., 'returns a success flag') for completeness.

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% (all three parameters have descriptions). The description adds no extra meaning to parameters beyond what the schema provides, so the baseline score of 3 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') and the resource ('screen'). It also explicitly mentions the pairing with screen_record_stop, which distinguishes it from sibling tools. The verb-resource pair is specific and unambiguous.

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 indicates when to use this tool ('Start recording') and that recording continues until stop is called, implying a pairing. However, it lacks explicit guidance on when not to use it or alternatives (though no direct alternative exists). The context is clear but not exhaustive.

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