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

With no annotations, the description carries the full burden. It does disclose the return payload (array of text/url pairs plus a count) and the free-trial payment terms, which is real value. However, it says nothing about behavior on malformed input, duplicate links, or which of the three aliased parameters is authoritative.

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?

One front-loaded sentence covers purpose and return shape, with the trial-call note trailing. Efficient and non-redundant, though the currency emoji note is promotional rather than operational.

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?

No output schema exists, and the description does explain the return value, which is the right call. But for a three-parameter tool with zero required fields and no annotations, leaving the parameter set ambiguous and offering no usage context makes it only minimally complete.

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% across three string parameters (md, text, input) with none required. The description's phrase 'from text' at best loosely gestures at one of them and leaves md and input completely unexplained, including whether they are aliases or alternatives. It does not compensate for the coverage gap.

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 ('Extracts Markdown links of the form [text](url) from text') and even describes the output shape, which an agent can act on. It does not differentiate itself from nearby siblings such as x402-extract-urls, x402-markdown, or x402-markdown-toc, so it stops short of a 5.

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?

No when-to-use guidance at all: no mention of when this beats x402-extract-urls or x402-html-text-extract, no prerequisites, no input constraints. The only extra statement is a pricing note, which is not usage guidance.

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