capture_window

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

The description discloses that no Slack call is made, so no token or scope is needed, and that the screenshot is returned for inspection. However, it does not describe the output format or any side effects, which is a gap given no annotations are provided.

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 two sentences, front-loaded with the core purpose, and each sentence provides unique value (purpose then usage pattern). No wasted 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?

The description explains the core functionality and usage pattern well, but it does not mention the return value format. Given the schema fully documents parameters, the description is mostly complete for a tool with no output schema.

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%, so the schema already documents all parameters. The description adds no additional meaning about parameters like 'trim', 'window', or 'allow_fullscreen', thus no added value beyond the schema baseline.

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 it captures a screenshot without posting, and distinguishes from the sibling 'capture_window_and_post' by noting it does not call Slack and does not require tokens/scopes.

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 suggests composing with 'send_to_slack' to inspect and optionally post the image, indicating when to use this tool versus alternatives. However, it does not explicitly list exclusion criteria or enumerate sibling alternatives.

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