glass_screenshot

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

No annotations are provided, so the description bears full responsibility. It discloses important behaviors: clipping on off-display capture, returned width/height reflecting actual captured size, and error only on fully off-screen surfaces. This goes beyond a basic statement of function.

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 primary action, and contains no filler. Every sentence adds value, making it highly efficient for an AI agent to parse.

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 key behaviors and parameter usage, but it lacks specification of the full return value structure (e.g., whether it returns base64 image data, file path, etc.). Given there is no output schema, this omission leaves a gap for an AI agent trying to use the result. However, the tool's simplicity and the description of width/height partially mitigate this.

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%, but the description adds meaningful context: 'region' is window-relative, 'window_id' allows capturing a non-active window without altering focus, and the clipping behavior description clarifies the semantics of the returned dimensions. This enhances understanding beyond the schema.

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 uses specific verbs ('Capture') and a clear resource ('app window', optional 'region'), and the tool name 'glass_screenshot' clearly indicates its purpose. It is easily distinguished from siblings like 'glass_a11y_snapshot' (accessibility) and 'glass_baseline_save' (visual baselines).

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 provides clear context for when to use the tool (to capture a screenshot, optionally of a sub-region or from a specific window). It does not explicitly list when not to use it or name alternatives, but the sibling list contains no other screenshot tools, making its usage scope unambiguous.

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