Ask several sessions one question

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

With no annotations, the description carries the full burden and does substantial work: it discloses blocking/wait semantics, the timeout cap, partial-result behavior ('says who did not answer'), and a privacy-relevant side effect ('the question and replies are sent to that model'). It does not cover permissions, rate limits, or whether the reply is delivered as a message.

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-loads the action and stays dense with facts per sentence, but the pick='best' explanation is restated from the schema and the Claude-session caveat arrives as a trailing aside, adding length without new routing value.

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, so the description must explain returns, and it does: answers returned together, non-responders identified, and the optional best-reply opinion with probabilities plus the caveat that every reply is still shown. An agent has enough to invoke and interpret results 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%, so the baseline is 3, but the description adds meaning the schema lacks: that '#channel' targets a channel's subscribers and that refs come from list_peers, plus the consequence of pick='best'. The rest largely restates schema text.

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+resource with scope: 'Send one question to several sessions at once, wait for their answers, and get them back together.' It also distinguishes itself from siblings by naming the one case it does not cover (Claude-to-Claude) and routing that case to SendMessage.

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?

Gives clear conditions for use (one question fanned out to multiple sessions, max 16, blocking with a timeout) and an explicit when-not with an alternative ('A Claude session cannot ask Claude sessions this way... use SendMessage'). It stops short of contrasting against broadcast, which an agent might otherwise consider for a similar fan-out.

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