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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the description adds context about supported features (device emulation, dark mode, etc.) but does not disclose behavioral traits like rate limits, page load delays, or error handling. It neither contradicts annotations nor adds critical behavioral details.

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 extremely concise: two sentences with no filler. The first sentence states the core purpose, and the second lists features. Every word earns its place.

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?

Given 13 parameters and no output schema, the description covers the major feature areas (output formats, device emulation, full page, etc.). It does not explain return value structure or error scenarios, but for a capture tool with good annotations, this is mostly sufficient.

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% with each parameter having its own description. The tool description adds a high-level list of supported features (e.g., 'cookie banner removal') but does not provide detailed semantics beyond what the schema already offers. Baseline 3 is 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?

The description clearly states the tool's purpose: 'Capture a screenshot of any website' with specific output formats (PNG, JPEG, WebP, PDF). This is a specific verb+resource pair that distinguishes it from sibling tools like batch_screenshots or extract_content.

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 lists many features but provides no guidance on when to use this tool versus alternatives (e.g., batch_screenshots for multiple URLs, check_screenshot_cache for cached versions, extract_content for text). No exclusions or context for selection are given.

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