Join tribe

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

Annotations already mark this as a non-read-only mutation, but the description goes further: it discloses the exact 404 behavior for private tribes (indistinguishable from a non-existent tribe) and specifies the return shape {tribe: uuid, member: true, role}. It also implies state change (membership) without contradiction.

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 sentences carry purpose, differentiation, behavior, and return value with no filler. The core action is front-loaded, and each sentence 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?

With no output schema, the description provides the return shape, covers error behavior (404), and addresses usage alternatives. For a single-parameter mutation tool, nothing an agent needs to call it correctly is missing.

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 schema covers 100% of the parameter (tribeId) with a description that already explains the UUID source and the pending-invitation requirement. The description adds general public/private context but does not enrich the parameter beyond the schema, so the baseline of 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?

The description states a clear verb-resource pair ('Join a tribe') and immediately distinguishes it from sibling tools: tribeunal_join_jury (case-jury seat) and tribeunal_invite_jurors (recruiting a tribe onto a case). It also explains what a tribe is ('standing group'), so an agent can tell it apart from every sibling without opening 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?

It explicitly names two alternatives and the conditions that select them, and explains public vs. private membership rules. It also notes the 404 behavior for private tribes without an invitation, which serves as a rejection signal. Finally, it mentions the complementary action (tribeunal_leave_tribe) for later use.

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