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

readOnlyHint already covers safety, and the description adds real context beyond that: sort order (newest first) and what a message record contains (direction, body, delivery state). With no output schema, this return-shape disclosure is the main behavioral signal; pagination behavior itself is only implied.

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 short sentences, front-loaded with the core purpose and ordering. The trailing API endpoint line is boilerplate but compact and occasionally useful for mapping errors.

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 read-only list tool with a fully documented two-param schema, the definition covers purpose, ordering and record contents. It is slightly thin on what the 'events' part of the timeline contains and takes return shape no further than the message fields.

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%, with both the conversation id and the cursor (including how to read it from view.next) already documented. The description adds no parameter meaning of its own, so 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 and resource (get messages and events of a conversation) and adds ordering ('newest first'), which separates it from textus_get_conversation (metadata) and textus_get_conversation_stats. It never names those siblings explicitly, so an agent still infers the boundary.

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 (fetch a conversation's message/event history) but gives no explicit when-to-use/when-not guidance relative to the siblings it sits beside, such as textus_get_conversation or textus_get_conversation_stats.

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