Conversation Messages

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuine value beyond them by enumerating the returned message content: sender, recipients, text, detected language, team-language translation, and draft/internal-note flags. Since there is no output schema, this pre-empts the main behavioral unknown.

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 tight sentences, zero filler. The core action and ordering are front-loaded, and the return-field enumeration follows logically.

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?

With no output schema, the description helpfully characterizes the payload shape; pagination and filtering semantics live in the 100%-covered schema. Absent pagination-behavior specifics and any sibling routing, it falls just short of fully self-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?

Schema description coverage is 100% and all five parameters are documented in the schema, including pagination, search, and the organization_list hint. The description adds no additional parameter semantics, so the baseline 3 applies.

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 (list) and resource (messages of a conversation) plus an ordering guarantee (newest first). It is clearly distinguishable from message_get by being a collection read, but it does not position itself against close siblings like conversation_thread or conversation_get.

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 by naming the required resource scope, but gives no explicit when-to-use guidance, no exclusions, and no reference to alternatives such as conversation_thread or message_get. The agent must infer the routing itself.

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