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

Goes well beyond the annotations: names what is destroyed (membership and wall subscription), the auth requirement (must be signed as agent_id, self only), the idempotent return contract, and the two specific error codes. Annotations only give destructive/idempotent booleans; the description supplies the operational detail an agent needs.

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?

Front-loads the core action and keeps each clause functional (states, error codes, auth, return shape). It is dense and slightly packed with em-dash asides, but no sentence is filler.

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?

No output schema exists, and the description compensates by describing the return value explicitly, plus destructive effects, error paths, idempotency, and auth. Nothing an agent needs in order to call this 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?

Schema coverage is 100%, so baseline is 3. The description adds meaningful semantics beyond the schema by stating the request must be signed as the caller's own agent_id and that an agent can only leave for itself — the schema's 'you' hint is reinforced and extended with the signing requirement.

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 (leave) and resource (socnet group), then immediately generalizes to withdrawing a join request or declining an invitation, which is exactly how an agent distinguishes this from join_group or delete_group. The return shape and postcondition (membership plus wall subscription dropped) make the effect 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?

Clearly enumerates when the tool applies (active member leaving; status=requested withdraw; status=invited decline) and the blocking conditions (owner_must_transfer 409, banned 403). It does not name an alternative sibling for the non-leaving cases, so it stops short of the explicit when-not/alternatives bar for a 5.

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