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

The description discloses billing costs (300 micro-USD per successful call), prerequisite preparation, and idempotent recovery behavior. These traits go beyond the annotations, which only indicate idempotency. The description aligns with idempotentHint and adds context about billing side effects, fulfilling the disclosure requirement.

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 three sentences long, front-loading the primary function then adding essential context about cost and prerequisites. Every sentence carries necessary information without redundancy, though it could be slightly more compact by merging the first two sentences.

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 the tool's complexity (nested input, paid service, prerequisites) and the presence of an output schema, the description covers all critical aspects: purpose, cost, preparation, authorization, and idempotency/recovery. The only minor omission is explicit error handling, which is not required given the output schema.

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?

The schema already describes requestId and maxPriceMicroUsd with notes about persistence and recovery. The description adds a reference to prepare and billing, but does not elaborate on html or baseUrl usage. With schema coverage at 67% and the description providing no additional parameter details, the baseline of 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 states a specific verb ('Extract') with a clear resource ('title, description, canonical URL, language and social metadata') from supplied HTML. This clearly differentiates it from siblings like html_headings or html_jsonld, which target other specific content 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?

Provides clear operational context: requires agent_utilities_prepare, existing credits, and a private Authorization header. Also explains recovery semantics and billing. However, it does not explicitly contrast with alternative html_* tools, though the purpose makes the intended use obvious.

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