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

With no annotations, the description carries the full behavioral burden. It discloses the cost ($0.001 USDC on Base via x402) and that it handles a single public URL, but omits timeout behavior, error handling, and explicit read-only safety confirmation.

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?

Three short sentences, front-loaded with purpose. The middle sentence about the scalar contract and buyer runtimes is relevant but slightly meta; overall efficient and free of waste.

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 lists the extracted data types (metadata, OpenGraph, JSON-LD) and the cost. However, it lacks detail on return format, timeout parameter behavior, and potential errors, leaving some gaps for an agent.

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 only 50% (url is described, timeout_seconds is not). The description adds no meaning beyond the schema, merely restating that it takes one public URL and is scalar; it does not explain timeout_seconds or its bounds.

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 first sentence clearly states the verb (Extract) and resource (webpage metadata, OpenGraph, JSON-LD) for one public URL. It does not explicitly differentiate from sibling tools like extractWebpageMetadata or html-metadata, so an agent must infer the distinction.

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 gives no guidance on when to use this tool versus alternatives such as extractWebpageMetadata or web-reader. It only states the contract (single-URL) and cost, leaving the selection condition to inference.

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