take_region_screenshot

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

The description discloses that the tool is interactive, blocks until selection, and requires external tools (grim, slurp). However, it does not specify what happens to the captured screenshot (e.g., saved to a file, returned as data), leaving a gap in behavioral understanding. Since there are no annotations to provide additional information, the description carries the full burden and is adequate but not complete.

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 extremely concise: two sentences that pack all essential information—purpose, mechanism, blocking behavior, cancellation, and dependencies. No unnecessary words.

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?

Given the tool has no parameters, no output schema, and low complexity, the description covers the core behavior. It could be enhanced by specifying the output format or location of the screenshot, but for a minimal tool it is sufficiently complete.

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 input schema has no parameters, so schema_description_coverage is 100%. The description does not need to add parameter semantics, but it effectively explains that no parameters are required due to interactive selection. Baseline for zero parameters is 4, and the description meets this standard.

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: interactively capture a screen region. It specifies the tools used (slurp for selection, grim for capture) and distinguishes from siblings like 'screenshot_active_window' or 'take_screenshot' by emphasizing the interactive, region-selection aspect.

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 clearly implies when to use this tool (for interactive region capture), mentions that it blocks and can be canceled with Escape, and lists required dependencies. It does not explicitly contrast with sibling tools or state when not to use it, but the context is clear enough.

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