Add / remove / promote group members

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

With no annotations, the description carries the full burden of behavioral disclosure. It does this well by stating an auth requirement (admin status) and a specific failure mode (403 for privacy-blocked adds) with an actionable fallback. It does not mention success responses or other potential errors, but the disclosed details go well beyond a bare mutation statement.

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 with zero fluff. The first sentence states purpose, the second adds the auth prerequisite, and the third gives an error-handling fallback. Each sentence earns its place, and the most important information is front-loaded.

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 three-parameter mutation tool with no annotations and no output schema, the description covers the essential operational facts: what the tool does, the admin requirement, and how to handle a likely error. It lacks an explicit statement of what a successful call returns, but the absence of an output schema and the presence of a clear action enum make this a minor 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 description coverage is 67%, which is moderately high. The participants parameter is well-described in the schema ('People — names, phone numbers with country code, or jids'), and the action enum is self-explaining. The description text does not add parameter-level detail beyond the schema, so the baseline score of 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 opens with a precise verb and resource: 'Add people to a group, remove them, or change who is an admin.' This clearly covers all four actions in the enum (add, remove, promote, demote) and distinguishes the tool from sibling group-management tools like create_group and update_group, which operate on group settings rather than membership.

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 provides explicit when-to-use and when-not-to-use guidance: 'You must be an admin of the group' sets the precondition, and 'A person whose privacy settings block being added returns status 403 — send them the invite link instead' names a concrete alternative (the group_invite_link sibling tool) and the condition that triggers it. This is exactly the kind of decision-relevant routing an agent needs.

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