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

Annotations cover only the safety profile (readOnly, not destructive, non-idempotent, open world), leaving the heavy lifting to the description, which delivers: timeout semantics, the full event taxonomy, `humans_present`/`addressed_to` fields, `stale_error` conditions, and explicit error handling (404 = unknown session after leave; 5xx/503/network errors leave the session valid). This is unusually rich behavioral disclosure well beyond the annotations.

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?

The core instruction is front-loaded in the first clause, but the rest is a single mega-sentence with a deeply nested parenthetical cataloguing every event type. Since an output schema exists, much of that event enumeration is redundant with structured return data, and the run-on nesting makes it hard to parse.

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 complex long-poll tool this is nearly complete: session provenance, timeout bounds, event semantics, and error/session-validity rules are all present, and the output schema covers return shapes. The remaining gap is operational follow-up guidance (what to do after `ended`/`timeout`, concurrency limits), which leaves it just short of full completeness.

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% and both parameters are documented in the schema, including the default (45) and maximum (50). The description repeats the timeout cap and the session origin but adds no syntax or format meaning beyond the schema, so the 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 opening sentence gives a precise verb+resource+scope: block up to `timeout` seconds for the next event in the call and return it. It clearly distinguishes the operation from mutation tools like say/send_data. It does not, however, name or contrast itself with close siblings such as `activity` or `status`, which is what a 5 would require.

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?

Usage is only implicit: the event semantics (e.g. `timeout` with reconnect, `superseded` when a newer next call replaces this one) imply a polling loop and discourage concurrent calls, but the description never states when to call this versus `activity`/`status`, nor what to do after `ended` or an error. Guidance is inferable but not explicit.

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