screenshot_window

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

Annotations declare readOnlyHint=false, destructiveHint=false, openWorldHint=false, so the agent knows this is non-destructive but has a side effect. The description adds nothing about that side effect: it does not say whether the image is saved to a file, returned as data, or placed on the clipboard (especially relevant given screenshot_to_clipboard exists as a sibling). No capture timing, display, or failure behavior is described.

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?

A single well-formed sentence with the scope qualifier up front and zero filler. For a zero-parameter tool this is appropriately sized.

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 simple zero-param capture tool with no output schema, the missing piece is the destination of the captured image and any return value, which the description is silent on. Annotations cover the safety profile, but the agent still cannot predict what it gets back or where the file lives.

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 takes zero parameters, which is the baseline-4 case; there are no argument semantics to explain. The description correctly conveys that the target is implicit ('currently focused window') rather than selectable.

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 ('Take a screenshot of the currently focused window'), and the scope qualifier 'currently focused window' implicitly separates it from screenshot_full, screenshot_monitor, and screenshot_region. It never names those siblings, so differentiation relies on the agent noticing the scope wording.

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 scope phrase implies when this tool applies (window-level rather than full-screen/monitor/region capture), but there is no explicit when-to-use, when-not-to-use, or named alternative. With four closely related screenshot siblings, an explicit routing sentence would have been valuable.

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