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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses the x402 pay-per-use model and exact cost (0.03 USDC on Base), which is valuable beyond the schema, but it does not describe auth/payment failure behavior, rate limits, or exactly what a returned 'sheet' contains.

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 tight sentences with no filler: purpose first, then input format, then payment model. Every element earns its place.

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 low-complexity, one-parameter tool with no output schema and no annotations, the description covers the core action, the input, and payment terms. It says sheets are returned, though it could say a bit more about the returned sheet structure or whether payment must be settled before the call.

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 input schema only describes the single parameter as 'service input', which is uninformative. The description compensates by clarifying 'input=URL', adding concrete meaning beyond the schema text.

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 ('Descarga un .xlsx por URL y devuelve sus hojas'), making it immediately distinguishable from sibling readers like leer-pdf, leer-docx, and leer-url. An agent can tell 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?

The description implies usage through the .xlsx resource type, but it never states when to use this tool instead of siblings such as leer-pdf, read-url, or doc-extract. No exclusions or alternatives are named.

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