pmux_browser_screenshot

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

With no annotations, the description carries full behavioral burden. It covers return formats (default PNG image content vs. {saved, bytes} with savePath), full page option, Electron-only constraint, and specific error codes. This is comprehensive for a screenshot tool.

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 concise—three sentences with no wasted words. It is front-loaded with the main action, then details default, savePath, full, and constraints. Every sentence adds essential information.

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 tool has no output schema, so return values are described adequately. Prerequisites (workspaceId, tabId from specific tools) are mentioned in the schema. The description covers Electron-only and error codes. No mention of rate limits or auth, but these are not critical for a screenshot 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 100%, so baseline is 3. The description adds significant value by explaining the conditional behavior of savePath (changes return type) and full (captures beyond viewport), which goes beyond the schema's brief descriptions.

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 tool's purpose: 'Screenshot a web-browser tab.' The verb 'Screenshot' and resource 'web-browser tab' are specific and unambiguous. Among the sibling tools, no other tool captures a full browser tab screenshot, so it is well-differentiated.

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 default behavior and alternatives (savePath, full). It also notes Electron-only requirement and error codes (503 hard, 409 transient). However, it does not explicitly compare to other tools like pmux_capture_pane or state when not to use this tool.

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