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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety bar is low. The description adds genuinely new context: the output is identical bytes to /join.txt (deterministic content) and that it performs no enrollment action, clarifying that it is inert output rather than an operation.

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 short sentences, front-loaded with the read-only nature and the key caveat (does not join you). Every clause carries information; no filler.

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 parameters, no output schema, and full annotation coverage, the description gives enough: what it returns, its equivalence to /join.txt, and that it is not an action. Minor gap is that it does not explain the format of the returned prompt beyond the file equivalence.

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 tool takes zero parameters, so the baseline is 4. There is nothing param-related to explain or compensate for, and the description appropriately does not invent parameter guidance.

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 clear verb+resource: it returns a door/join prompt text, with the added clarification that it does not perform the join itself. However, the phrase 'one-paste door prompt' is domain jargon that doesn't explicitly differentiate it from siblings like room_join_kits or room_join_packet.

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 context ('follow its steps to enroll' and the explicit 'it does not join you' exclusion), which is a useful negative clarification. But it never names an alternative tool or states when to prefer a sibling such as room_join_kits, so routing guidance is only implied.

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