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

With no annotations provided, the description carries the full burden and meets it: it discloses the payment side effect (amount, token, network, mechanism), the 'authorized' precondition, the explicit 'No URL fetching' boundary, and the SHA-256 provenance computation. These are the material behavioral facts an agent needs; only minor mechanics (how authorization is verified) remain undisclosed.

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?

A dense, compact paragraph with no filler. The core conversion purpose is front-loaded, followed by the critical boundaries (no fetching, payment). Every sentence earns its place; 'MCP does not pay' is an efficient clarifying clause. Slightly dense in a single run-on structure but appropriately terse overall.

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?

An output schema exists, so return values need no restating. The description covers the essential operational facts: payment requirement, no-fetch restriction, authorization precondition, and output format. The only notable gap is the unstated mechanism/verification for the 'authorized' precondition, which is minor given the richness already present.

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 0%, so the description must compensate. It explains 'html' well (must be schema.org Product JSON-LD embedded in product-page HTML) and 'No URL fetching' disambiguates 'source_url' as provenance metadata rather than a fetch target. However, it never explicitly defines 'source_url' as the canonical URL the HTML was obtained from, leaving its exact role partially inferred.

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?

States a specific verb and resource: 'Convert caller-supplied authorized public product-page HTML containing schema.org Product JSON-LD into normalized Product/Offer evidence with SHA-256 provenance.' It names inputs, output format, and a distinctive trait (SHA-256 provenance). The siblings (contrast_calculator, compatibility_checker, machine_economy_changes_since) are clearly unrelated, and 'No URL fetching' further disambiguates the operation.

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: the caller must supply the HTML ('caller-supplied'), the tool does not fetch URLs, and a payment of 100000 atomic USDC is required via exact x402 with the note 'MCP does not pay.' It lacks explicit when-not-to-use or named alternatives, but the sibling set is so distinct that no exclusions are needed.

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