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

Annotations only give readOnly=false, idempotent=false, openWorld=true; the description adds the real behavioral payload: it blocks up to timeout_s (max 25), returns only expert and registry messages after after_seq, hands back last_seq for the next call, and imposes an anti-impersonation / anti-paraphrase constraint. This is consistent with (and richer than) 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?

Four compact sentences, front-loaded with the action and return contract, then the safety rules. No filler; every clause carries operative information an agent needs (roles, timeout cap, cursor chaining, relay rule).

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 output schema, the description adequately covers the return contract (expert + registry messages, plus last_seq) and the blocking/sequencing model. It leaves open the timeout-expiry case (empty vs. partial return) and the meaning of job_id/customer_token, minor gaps for a 5-param tool.

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 only 20% (just after_seq), and the description compensates well: it explains the role enum values via 'your user's turn (role user) or your own (role assistant)', restates the timeout_s max of 25, and clarifies the after_seq/last_seq cursor loop. job_id and customer_token remain unexplained, keeping it short of a 5.

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 precise compound action (post a turn, then wait for expert messages) on a specific resource (the open room), and distinguishes the two legal roles ('user' / 'assistant'). An agent can tell this apart from ask_human, call_human, or deliver without opening a schema.

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 establishes the calling context (post your turn to the open room and block for the expert's reply) and gives hard rules ('never post as the expert', 'never paraphrase — relay'). It does not, however, explicitly contrast itself with siblings like ask_human, call_human, or request_review, so the agent must infer which channel to pick.

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