extract_structured_metadata

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

With no annotations provided, the description carries the full burden. It states the core operation (extract and validate) and discloses a cost requirement. However, it does not describe important behavioral aspects such as required payment signature handling, failure modes for malformed HTML, or whether the tool is read-only. The cost disclosure adds some value but the behavior remains under-specified.

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 a single sentence that front-loads the main action and resource types. The parenthetical cost note is relevant but slightly tangential to the core purpose. No filler or redundancy, and it is compact enough for quick parsing.

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 no output schema and no annotations, the description is incomplete. It does not state what the tool returns, how to structure the payload to achieve the described extraction, or how payment is integrated. An agent would need to infer too much about the input format and output contract to invoke it correctly with confidence.

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%, so the baseline is 3. The schema's payload description is generic ('Input parameters or JSON string payload'), and the tool description does not clarify what the payload should contain (e.g., raw HTML body or a structured JSON with a URL). The description adds the cost figure, which relates to paymentSignature, but does not illuminate the payload format, leaving the schema to carry the load.

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 names a specific verb (extracts/validates) and precise resources (OpenGraph tags, JSON-LD schemas, Twitter cards, microdata) from a defined source (crawled webpage bodies). This clearly distinguishes it from sibling extract_* tools like extract_exif_geolocation or extract_sitemap_hierarchy, which target different data types.

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?

Usage is implied by the clear purpose, but there is no explicit guidance on when to choose this tool over alternatives, nor any exclusion conditions. The cost note '(0.01 USDC on Base L2)' is a practical consideration, not a usage guideline. It does not mention complementary tools like html_clean_boilerpipe_extractor for preprocessing.

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