Listar DMs

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuine context beyond the schema: result ordering (most recent to oldest), the data returned, and critically the 'So em modo user' authorization constraint. It does not mention rate limits or paging behavior.

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?

A single dense sentence that front-loads verb, resource, ordering, and returned fields before closing with the mode constraint. Efficient with no filler, though the run-on structure slightly reduces scannability.

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 4-param, zero-required, read-only list tool with no output schema, the description covers the essentials: what is listed, ordering, key return fields, and the user-mode requirement. The main gap is the lack of disambiguation from the 'inbox' sibling.

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%, so the schema already documents limit, query, format, and onlyUnread. The description only loosely parallels the schema by describing the unread concept ('se ha algo nao tratado') and ordering, which is adequate but adds little beyond the structured fields.

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 (Lista) and resource (conversas diretas / DMs e grupos), plus the ordering and the fields returned (channelId, participantes, ultima mensagem, nao tratado). Highly specific, though it never differentiates itself from the sibling 'inbox', which could plausibly overlap.

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?

Adds one real usage condition: 'So em modo user', which tells the agent this is unavailable outside user mode. However, it offers no guidance on when to prefer this over inbox, read_messages, or open_dm, so routing between the DM-related siblings is left to inference.

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