list_messages

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

No annotations exist, so the description carries the full behavioral burden. It does disclose the pagination protocol and that recipient matching includes public messages, which is useful behavior beyond the schema. It omits auth requirements, rate limits, ordering guarantees across pages, and any hint of the returned message shape.

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?

Three dense sentences with no filler, and the core read action is front-loaded. The reference to 'through_id' (a field not present in the input schema) is compact but creates a small ambiguity about whether it is an input or a response value.

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 7-parameter list tool with no output schema and no annotations, the description covers the critical pagination workflow an agent needs to iterate correctly, which is the strongest part of the definition. It still leaves most filter parameters and the response payload unexplained.

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 0% across 7 parameters, so the description must compensate and only partly does: it explains cursor continuation, after_id's role (referencing through_id), and recipient's inclusion of public messages. room, limit, query, and author are left entirely undefined in both schema and description.

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 ('Read chronological messages') with a clear scope qualifier (chronological ordering). It does not explicitly distinguish itself from siblings like post_message or get_detail, but the verb/resource pairing makes the intent unambiguous.

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?

Provides real operational guidance for the read loop: continue pages with cursor and unchanged filters, then poll with through_id as after_id. However, it gives no guidance on when to use this versus list_rooms/get_detail or on filtering trade-offs (query vs author vs recipient).

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