list_documents

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

Annotations already declare readOnlyHint=true, so the description only needs to add context beyond that. It mentions the source 'buzón' and gives a specific filter example, but does not describe pagination, sorting, or response format. The additional context is useful but not comprehensive.

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?

The description is very short (two sentences) and front-loads the core functionality. There is no wasted text, though the Spanish language might be a minor barrier for non-Spanish agents. Still, it is appropriately sized.

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?

Given the tool has 9 optional parameters and an output schema, the description is insufficient. It omits details on date filtering, keyword search, hashing, sorting, pagination, and return values. The output schema exists but is not referenced, leaving agents to infer behavior.

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?

With 0% schema description coverage, the description must compensate. It explains 'assigned' (boolean filter) and 'extension' (with format example), but 7 of 9 parameters (initial_date, end_date, keyword, hash, sort, page, page_size) are left unexplained. The description covers only about 22% of parameters.

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?

The description states 'Lista documentos del buzón' (lists documents from the mailbox), clearly indicating a listing action on a specific resource. While it does not explicitly differentiate from sibling list tools like list_accounts, the resource is distinct enough.

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 hints at filtering use cases (assigned=False for pending expenses, extension example) but provides no guidance on when to use this tool versus alternatives like get_document for a single document or other list tools. No exclusions or prerequisites are mentioned.

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