capture_screenshot

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

No annotations are provided, so the description carries full burden. It discloses the return format (base64 image data with mime type) and error conditions (isError if not connected or invalid node). It does not discuss potential side effects (assumed read-only) or rate limits, which leaves some gaps.

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 and well-structured with clear sections: purpose, prerequisites, return value, usage hints, errors. Every sentence serves a purpose with no superfluous text.

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 is provided, but the description adequately explains the return value. It covers prerequisites, error handling, and integration with other tools. Minor improvements could include size limitations or additional limitations, but overall it's complete for a tool with simple parameters.

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 parameters already have descriptions. The tool description adds minimal new meaning beyond what's in the schema (e.g., format preference, omitting nodeId for full page). Baselines at 3 since schema does the heavy lifting.

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 action ('Capture a screenshot') and the resource ('Figma node or current page'). It distinguishes from sibling tools by being the only screenshot tool, and provides guidance on format preference (SVG vs PNG) which adds clarity.

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?

Explicit prerequisites are given (bridge + plugin connected, node IDs from other tools). It also positions the tool in the self-heal loop and suggests feeding output into analyze_design. However, it does not explicitly state when not to use this tool or mention alternatives.

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