join_group

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

With no annotations, the description carries full responsibility for behavioral disclosure. It reveals an important trait: if the group requires admin approval, the request will be pending. It does not mention other potential side effects like notifications or permissions, but the provided detail is sufficient for a simple join operation.

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?

The description is two sentences long, front-loaded with the main action, and every sentence adds value. No unnecessary words or 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?

Given the tool has one simple parameter, no output schema, and no annotations, the description provides all necessary context: the invite link format, the pending approval behavior, and a follow-up action. Nothing essential is missing for an agent to use this tool correctly.

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 input schema already fully describes the sole parameter 'uri' as a group invite link starting with https://signal.group/#. The description repeats this format but does not add additional semantic meaning beyond the schema, so baseline 3 is appropriate.

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 clearly states the tool's purpose: joining a Signal group via an invite link. It specifies the exact resource (Signal group) and action (join), using a specific verb. This distinguishes it from sibling tools like 'create_group' or 'leave_group'.

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?

The description explains when to use the tool (when you have an invite link) and provides a clear next step (use list_groups to find the group_id). However, it does not explicitly mention when not to use it or suggest alternatives for other joining methods.

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