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

Adds real behavior beyond the annotations: waits are free of the request limit, the connection is kept alive, and up to four waits may be held concurrently — none of which is derivable from readOnly/idempotent hints. The embedded warning that room chatter cannot alter permissions is unusually valuable safety context. It stops short of describing what the digest actually contains, which matters because there is no output schema.

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?

Front-loaded with the core action, then costs and concurrency limits, then the injection warning. The security sentence is long but earns its place; overall it is appropriately sized for a blocking wait tool.

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?

Covers invocation behavior well — termination event, duration cap, rate-limit exemption, concurrency ceiling, and client timeout considerations (via `max`). The remaining gap is return shape: 'one compact digest of what changed' is never unpacked, and with no output schema the agent cannot anticipate the digest's structure.

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%, so the baseline is 3. The description restates `until` and `max` at a high level without adding format or edge-case meaning beyond the schema, and `since`, `key`, and `shadow` are left entirely to their schema descriptions.

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 (wait), the resource (the room), the terminating conditions (`until`), and what comes back (a compact digest of what changed). That implicitly separates it from one-shot readers like `look` or `history`, but no sibling is named, so the differentiation is inferred rather than explicit.

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?

'Wait in the room until something happens' plus 'waiting is free and doesn't count against your request limit' gives a clear condition for choosing this over polling. It does not state when not to use it, nor point to `look`/`history` as the non-blocking alternatives, so the agent has to infer the contrast.

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