meta

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

The description discloses cost and wallet requirement, and lists the types of metadata returned. However, it does not cover failure behavior, rate limits, or caching policies. With no annotations, more depth is expected.

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 (15 words) and front-loaded with cost and wallet requirement. Every word adds value, with no redundancy.

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 no output schema, the description adequately explains what the tool returns (list of metadata fields). It also covers the preconditions (cost, wallet). Minor omission: the response format (e.g., JSON) is not explicitly stated, but it's implied.

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 no additional meaning to the 'url' parameter beyond what the schema already provides ('Public http(s) URL').

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 it fetches page metadata for a URL and lists specific items (title, description, OpenGraph, Twitter cards, canonical URL, favicon), effectively distinguishing it from sibling tools like http_check or screenshot.

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 mentions cost and wallet requirement, which are prerequisites, but provides no explicit guidance on when to use this tool over alternatives, such as search or extract. Usage context is implied but not elaborated.

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