dm_messages_list

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description's addition of 'most recent first' provides useful ordering context beyond the schema. No contradictions, and the description adds value by specifying ordering.

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 a single sentence that is front-loaded with the core purpose and includes key filtering options. Every word contributes, with zero wasted text.

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 5 parameters (all described in schema), no output schema, and good annotation coverage, the description adequately covers core behavior but lacks details on pagination defaults or edge cases. It is minimally sufficient.

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 has 100% coverage with detailed parameter descriptions. The description mentions filtering by direction or status, which is already documented in the schema. It adds no new semantic meaning beyond what the schema provides.

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 clearly states the tool lists messages in a chat, orders them most recent first, and allows optional filtering. It uses a specific verb ('list') and resource ('messages in a chat'), distinguishing it from sibling tools like dm_message_get (single message) and dm_message_send (send).

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 for listing messages and filtering by direction or status, but it does not explicitly state when to use this tool versus alternatives like dm_message_get for a single message or dm_chat_get for chat details. No exclusions or prerequisites are given.

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