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

Describes the extracted metadata fields comprehensively and mentions pricing model. No annotations exist, so description carries full burden; missing details on error handling or rate limits, but overall sufficient.

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?

Very concise yet informative. Front-loaded with name and pricing, then lists capabilities. Every sentence adds value with no fluff.

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?

For a tool with one parameter and no output schema, the description fully explains input, output, and constraints. No significant gaps.

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% with one parameter 'url'. Description adds meaning by listing what metadata will be extracted from the URL, which is beyond schema's basic description.

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?

Clear verb-resource pair ('extract structured metadata'), specific about what it extracts (page title, meta description, OG tags, etc.), and distinguishes itself from sibling tools like assess or read by focusing on metadata extraction.

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?

Explicitly states when to use (give it a URL), that no account or API key is needed, and that payment is per call with x402. Provides clear context for usage.

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