well-004-html-to-markdown

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

Goes well beyond the annotations (which already cover readOnly/idempotent/non-destructive/openWorld) by disclosing cost ($0.005 USDC), the fetch allowlist (https only, no http/file/data/localhost/private IPs), body/timeout/redirect limits, warning behavior, no-warranty, and no-storage guarantees. These are operationally decisive facts an agent cannot derive from structured fields.

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?

Front-loads the core verb and price, then packs constraints tightly. It is dense and every clause carries information, though the allowlist details are repeated verbatim from the url schema, which is mild 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?

For a two-parameter tool with no output schema, the description supplies the missing return contract ({ source, url?, final_url?, content_type?, markdown, warnings }) plus all failure-mode constraints. Nothing an agent needs to invoke and interpret it is absent.

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 both parameters are already documented, including the 'preferred when both are set' rule. The description largely restates the schema rather than adding new parameter-level meaning, so the baseline of 3 applies.

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 HTML to tidy markdown') and immediately qualifies scope with the paid x402 mechanism and the two accepted input sources. An agent knows exactly what the tool does without opening the schema.

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?

Explicitly states the input contract: pass html and/or url, at least one required, and that html wins with a warning when both are set. That is a complete when/how decision tree with no inference required.

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