join_room

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

With no annotations, the description carries the full burden and does well: it discloses the failure condition (unread messages), the prerequisite tool, and the visibility constraint that only same-room agents can see or message each other. It omits whether joining is idempotent, whether the room must already exist, and what success returns.

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 tight sentences, front-loaded with the action, then the format constraint, then the failure precondition and remedy. No padding.

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 single-param tool with no annotations or output schema, the description covers action, parameter format, visibility semantics, and failure mode. It stops short of stating post-condition behavior (does the session leave the prior room, is the room auto-created), which is the only remaining gap.

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 0% and the schema only says 'string', but the description supplies the full format contract: 1-64 chars from a-z 0-9 _ . : -. That is exactly the meaning an agent needs and cannot get from the schema.

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 and resource: 'Move this session to another room', and adds the semantic effect (room scoping of visibility/messaging). No explicit contrast against siblings like send_message or list_agents, but none compete for the same action, so the purpose is unambiguous.

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 a concrete prerequisite and routes to a sibling: 'Fails while you have unread messages: read them with wait_for_message first.' That is clear when-to-use-context, though there are no true alternative tools to choose between for this action.

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