tell_people

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

Annotations already declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, so the write/external-visibility profile is covered. The description usefully adds delivery context (people read it on their phones) and DM visibility semantics for to:"owner", but says nothing about persistence, editability, rate limits, or whether the whole team sees the post.

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?

Three short sentences, front-loaded with the channel and payload form before the DM caveat; there is little filler. The phrase 'a heads-up' is slightly vague but costs almost nothing.

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 6-parameter tool with a nested summary object and no output schema, the description covers the main composition paths but leaves thread/in_reply_to unexplained and does not indicate what posting returns or whether it is fire-and-forget. Adequate but with visible gaps.

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?

With 50% schema coverage, the description compensates partially: it explains that summary+details and text are alternative composition modes and what to:"owner" does. However, thread and in_reply_to are undocumented in both places, and the summary object's internal guidance lives in the schema rather than the description.

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 description gives a concrete verb and channel ('Post to the team chat people read on their phones') and specifies the payload shapes ('summary plus details, or text') plus the DM variant for to:"owner". An agent can tell it is a progress/notification poster, though it never names the nearby siblings send_message, ask_people, or publish_handoff to disambiguate.

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 implied rather than stated: it suggests reporting what you did with someone's idea, a result, or a heads-up, and clarifies that to:"owner" is a private DM. There is no explicit when-to-use-this-vs-send_message/ask_people/publish_handoff guidance, which matters given three plausibly overlapping messaging siblings.

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