screenshot_region

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

The parenthetical '(opens slurp selector)' usefully discloses that the tool is interactive and blocks on a user selection — valuable context beyond the annotations, which only say it is non-read-only and non-destructive. But it never says what happens to the captured image (saved to disk, returned, or placed on the clipboard), which is the single most important behavioral fact for a screenshot tool with no output schema.

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 short sentence with the scope stated first and the interactivity note as a compact parenthetical. Nothing is wasted or buried.

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 tool the description covers what it does and how the region is chosen. The remaining gap is the fate of the resulting image, which matters more here because no output schema exists to convey it.

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?

Zero parameters, so the baseline of 4 applies; the description correctly implies the region is supplied interactively rather than via arguments.

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 (take screenshot) and a precise scope (user-selected region), which implicitly separates it from screenshot_full, screenshot_monitor, and screenshot_window. It does not name those siblings, so the differentiation is inferred rather than explicit.

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 phrase 'user-selected region' implies the condition for use, but there is no explicit when/when-not guidance and no alternatives are named despite four closely related screenshot siblings.

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