capture

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

No annotations are provided, so the description carries the full burden. It usefully discloses the immediate, single-image, image-return behavior, but omits the behavioral traits that matter for a screen-capture tool: OS screen-recording permission requirements, what happens when region='window' matches no title, and whether the call blocks for the delay. Those gaps keep it at a middling score.

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 short sentences, zero filler, with the core action and the return type front-loaded and the cross-reference to record placed second. Nothing is redundant.

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 3-parameter, no-annotation, no-output-schema tool, the description covers the action and the return type, which are the essentials. However it leaves the permission prerequisites and failure behavior for the window region unexplained, so an agent could still invoke it in a context where it silently fails.

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%, and each of the three parameters (delay, title, region) is documented with defaults and the enum values, so the baseline is 3. The description only adds the pointer that region semantics match record, which is useful but does not extend individual parameter meaning.

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 ('Capture a single screenshot'), names the immediate single-shot nature, and declares the return form ('return it as an image'). It also implicitly separates itself from the sibling record by tying region semantics to it while implying a one-shot rather than continuous operation.

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?

Usage is implied by 'immediately' and by the contrast with record, but there is no explicit when-to-use / when-not statement or guidance on choosing between capture, record, and list_windows (e.g., use list_windows first to find a title). The agent must infer the selection rule.

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