Join tribe

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

Annotations already flag it as a non-read-only, non-destructive mutation, and the description adds genuinely useful behavior beyond that: private tribes require a pending invitation, and joining without one returns a 404 indistinguishable from a nonexistent tribe. This prevents the agent from misinterpreting a 404 as a bad tribeId.

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 tight sentences with the core purpose first and the key edge-case behavior second. Every sentence earns its place with zero redundancy.

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-parameter mutation with full schema coverage and safety annotations, the description covers the main gotcha (private-tribe 404 ambiguity) that could trip up an agent. Minor gaps remain — behavior when already a member and the return format, given no output schema — but they are secondary for a simple join action.

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%: the tribeId parameter is fully documented with a UUID pattern and the instruction 'not its slug or numeric id'. The description adds no parameter-level detail, so the schema carries the burden; 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?

The description states a specific action — 'Join a tribe' — with a clear verb and resource. The action is naturally distinct from sibling tools like leave_tribe, get_tribe, and create_tribe, though no sibling is explicitly named.

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 context is implied through the invitation-only note, which tells the agent this tool succeeds for public tribes or pending invitations and fails with 404 otherwise. However, the description never explicitly addresses when to choose this over siblings like leave_tribe or invite_tribe_members.

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