capture-tab-screenshot

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

With no annotations, the description carries the full burden and does so well: it discloses the per-tab user authorization requirement, that authorization expires on navigation or close, the error-and-retry protocol, and the side effect that capturing brings the tab to the foreground. This is exactly the behavioral context an agent needs.

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?

Four short sentences, each load-bearing, with the core action front-loaded and the authorization caveat immediately following. No padding or redundant restatement of the name.

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?

No output schema exists, so the description would ideally state what is returned (image data and its format). Otherwise it thoroughly covers prerequisites, error handling, and side effects for a 4-parameter tool.

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 coverage is 75%, so scale, format, and quality are already documented in the schema. The description only touches tabId implicitly via 'by tab ID' and adds no syntax or semantics beyond what the schema provides, making the baseline 3 appropriate.

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 ('Capture') and resource ('screenshot of the visible area of a browser tab') with the scoping qualifier ('by tab ID'). An agent can distinguish this from get-tab-web-content or find-highlight-in-browser-tab without opening the schema.

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?

Explains the prerequisite (each tab must be authorized by the user via the toolbar button) and the retry flow after an authorization error. It does not name sibling alternatives such as get-tab-web-content for text extraction, so it stops short of full when-not guidance.

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