computer_screenshot

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

No annotations are provided, so the description carries the behavioral disclosure burden. It states the tool returns the current screen as an image and implies a read-only observation, but it does not explicitly mention side effects, permissions, or output format limitations. For a simple screenshot tool this is acceptable but not thorough.

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 short and front-loaded with the primary action in the first sentence. The second sentence adds the output type, and the third gives usage guidance. Minor redundancy exists between the first and second sentences, but overall it is 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 zero-parameter screenshot tool, the description covers the essential context: what it does, what it returns, and when to call it. There is no output schema, but 'as an image' is sufficient. Gaps such as image format or resolution are not critical for basic invocation.

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 tool has zero parameters, so the schema is fully covered and the description needs no parameter-level detail. The baseline of 4 applies because there is nothing missing for an agent to understand how to invoke it.

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 states a specific action and resource: 'Capture a screenshot of the current screen' and clarifies it returns an image. It is unambiguous about what the tool does, though it does not explicitly distinguish itself from sibling tools such as computer_get_desktop_state.

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 gives an explicit usage instruction: 'Always call this first to see what's on screen before performing any actions.' This provides clear context for when to use it, but it does not mention alternatives or when not to use it.

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