capture_screenshot

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

With no annotations, the description carries the full burden of behavioral disclosure. It discloses save location behavior, allowed-root restrictions, format options, and the return_image=false behavior. However, it does not specify the exact response structure (e.g., how the image is returned or what metadata fields are included) or default filename generation when path is a directory.

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 front-loaded with the core purpose and then efficiently details each parameter in separate lines. Every sentence adds necessary information without redundancy or fluff.

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 tool with no output schema and no annotations, the description covers the essential invocation details, constraints, and alternative routing. The main gap is the exact return structure (metadata fields, image encoding), which an agent might need to process the result correctly. Still, it is largely complete for a straightforward screenshot capture tool.

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 0%, so the description must explain all parameters. It does: path is described as a destination directory/file with resolution and allowed roots, format is enumerated as png/jpg/jpeg/bmp/webp, and return_image is explained as metadata-only when false. This fully compensates for the schema's lack of descriptions.

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 ('Capture'), resource ('the screen'), and outcome ('save it, and also return the image'), which is unambiguous. It also differentiates itself from the sibling tool measure by explicitly saying 'For numeric readings use measure, not this image.'

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?

Explicitly provides when-not-to-use guidance with 'For numeric readings use measure, not this image.' It also gives context for options like 'With return_image=false only the metadata is returned, without the image (saves tokens)', and explains path resolution against the invocation directory and allowed-root restrictions.

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