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

Annotations already declare readOnly/idempotent/closed-world, so the safety profile is covered; the description adds genuinely new behavior — a once-per-minute polling limit and the incremental-fetch semantics of the cursor. It still doesn't explain what "status" contains or how access is authorized when conversation_token is omitted.

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 purpose, then pagination, then the rate limit. Every sentence carries information; only the vague "and status" phrase dilutes it.

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?

No output schema exists, yet the description names both return components (messages, status), the paging model, and the polling constraint; the token/auth detail is fully covered by the schema. An agent has enough to call it correctly.

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 coverage is 100% and each parameter is well documented. The description only reinforces the 'after' cursor meaning already stated in the schema, adding no syntax or format detail beyond it, 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?

The verb+resource ("Returns messages and status") is clear, but it overlaps heavily with siblings read_messages and get_conversation_status, and the description never distinguishes itself from them. An agent cannot tell which of the three to call without opening schemas.

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?

It gives real usage guidance for pagination ("Pass next_cursor as 'after' to fetch only newer messages") and a polling cadence, but never says when to prefer this over wait_for_reply, read_messages, or get_conversation_status.

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