mesh_join_room

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

With no annotations the description carries the full behavioral burden and does well: it discloses that joining starts background watching, publishes a participant_joined event, and is idempotent — non-obvious side effects an agent must know. It stops short of describing the immediate return value/timeout behavior, keeping it from a 5.

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?

A single dense but well-ordered sentence followed by three terse clauses; the verb+resource is front-loaded and every phrase (idempotent, publishes participant_joined, follow-up tools) earns its place.

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 one-parameter join tool with no annotations and no output schema, the description covers initiation, side effects, idempotency, and lifecycle handoffs. It omits what the join call itself returns, which is the only meaningful 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 100% and the single parameter is already documented as 'The agents.room.<32 hex> topic.' The description adds only that the topic may come from mesh_rooms or out of band, which is useful provenance but not syntax beyond the schema. Baseline 3 applies.

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 ('Join a room') and immediately scopes the input by explaining where the room topic comes from. It names siblings (mesh_rooms, mesh_say, mesh_read_inbox, mesh_leave_room) so an agent can place it in the room lifecycle without opening other schemas.

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?

Explicitly states when to use it (a topic learned from central or out of band) and routes the agent to the right follow-up tools: mesh_say to talk, mesh_read_inbox to read, mesh_leave_room when done. This is a full when/next-step map, not just implied usage.

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