Listar mensajes

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context by listing what is returned (UID, date, sender, subject, flags, attachment presence) and explicitly stating that the message body is not downloaded. It does not, however, describe pagination or sorting order beyond 'most recent'.

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, front-loaded with the core action and scope, followed immediately by the key exclusion ('No descarga el cuerpo'). No filler or repetition.

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 simple read-only list tool with three fully documented parameters and no output schema, the description supplies the necessary return-field summary and the important non-behavior of not fetching bodies. An agent has enough to invoke it correctly without opening additional context.

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 description coverage is 100%, and all three parameters (limit, mailbox, unread_only) are already documented in the schema with constraints and examples. The description adds no parameter-level meaning beyond the schema baseline.

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 ('Lista los mensajes más recientes de una carpeta'), enumerates the returned fields, and implicitly distinguishes itself from body-fetching siblings by saying it does not download the body. An agent can tell this is a metadata-only listing tool.

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 when to use it — for recent-message metadata in a folder — and hints that body retrieval belongs to another tool. However, it does not explicitly name alternatives like get_message or search_messages, nor does it state when not to use this tool.

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