iam_chat_join

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

Discloses that joining another channel leaves the prior one, indicating a single active channel behavior. Also mentions the DM creation case. However, it does not mention permissions or side effects beyond switching, and annotations are absent so the description carries full burden.

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?

Two sentences, front-loaded with the core purpose and behavior; the conditional DM note is placed second. No filler.

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 the core joining behavior and the DM special case, and an output schema exists so return format is handled. However, it leaves the meaning of the channel parameter and allowed channel_type values unclear, which is a gap given no schema descriptions.

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?

The description explains the purpose of channel_type and with_agent in the context of creating a DM, but offers no definition for the channel parameter. With 0% schema coverage, it partially compensates for the lack of parameter documentation.

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 it joins a live channel and makes it active, with a clear note that joining another switches active channel. This distinguishes it from siblings like iam_chat_leave and iam_chat_subscriptions.

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?

Provides a specific usage condition for creating DMs ('Use channel_type=private and with_agent only to create a new DM') but does not state when to prefer this over alternatives like iam_chat_leave or iam_chat_tail. No explicit when-to-use guidance.

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