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 two real behavioral traits beyond the schema: the output is stripped of HTML/scripts, and each call is a paid x402 transaction (0.002 USDC on Base, pay-per-use). It says nothing about failure modes, timeouts, JS-rendered pages, or rate limits, so meaningful gaps remain.

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?

Two short telegraphic clauses, with the core behavior front-loaded ahead of the billing bracket. Nothing is padded, though the phrasing is terse enough to feel like a note rather than a definition.

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 one-param fetch-and-extract tool with no output schema, the description covers what comes back (clean text) and the billing model, which is adequate minimum context. It still omits how to distinguish it from the duplicate read-url sibling and offers no note on the response shape beyond absence of HTML.

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 labels the single parameter only as 'service input', which is uninformative despite nominal 100% coverage. The description adds the salient fact that this input is a URL, which is exactly the meaning an agent needs to construct the call.

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 ('Lee una URL') plus the returned artifact ('texto limpio sin HTML/scripts'), so the agent knows exactly what it gets back. It does not, however, distinguish itself from the near-identical sibling read-url, so sibling differentiation is absent.

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?

There is no when-to-use guidance at all: the description never says when to pick leer-url over read-url, leer-pdf, ocr, or doc-extract. Usage can only be inferred from the name/verb, and no exclusions, prerequisites, or alternatives are stated.

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