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

Beyond the annotations, the description discloses several non-obvious behaviors: the seal is published as a public verifiable fact, the original document is never uploaded (only the hash), the signing keys/algorithms used, and a 20/hour-per-origin rate limit. Notably it describes querying external drand/NIST beacons and a TSA while openWorldHint=false, which sits in tension with the annotation but is not a direct contradiction.

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 sentences and a constraint, with the core action and its guarantee front-loaded; every clause carries distinct information (mechanism, privacy, rate limit). No filler.

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 mutation tool with no output schema, the description says a signed act is created and published but not what the caller receives back (receipt, ID, proof payload, URL). An agent that needs to chain into verificar or report the seal reference is left guessing.

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 100%, so baseline is 3, and the description earns an extra point by clarifying the central parameter's semantics in context — 'No sube el documento: solo el hash' tells the agent the input must be a digest, not content. It adds nothing about quien/titulo, but those are already fully documented in the schema.

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 — seals a SHA-256 hash with a trusted timestamp — and goes further by naming the mechanism (FirmaRED signature, drand/NIST + TSA time sandwich, public verifiable fact). An agent knows exactly what operation this is, though the description never names a sibling (e.g., verificar) to contrast against.

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?

Usage context is implied (you seal when you need time-certain proof) and a hard usage constraint is given ('Máximo 20 por hora por origen'), but there is no explicit when-to-use/when-not or pointer to verificar for checking an existing seal. The agent must infer the workflow.

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