update_group

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

No annotations are provided, so the description carries the full burden. It discloses the key destructive behavior: 'user_ids: new, COMPLETE list of members — anyone not in it is removed from the group.' It also clarifies the 'name' field's behavior ('empty = leave alone'). However, it does not explicitly state what happens if user_ids is omitted or null, leaving a slight ambiguity about whether membership is left unchanged.

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 concise: a one-line summary followed by a clean args list. Each line carries information—nothing is redundant. It is front-loaded with the purpose and structured for quick comprehension.

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 mutation tool with no annotations and an output schema, the description covers the essential behavioral context (full replacement semantics, name handling) and points to an alternative. It could mention prerequisites or error cases, but given the tool's simplicity, it is reasonably complete. The absence of annotation forces the description to do more, and it delivers on the most critical aspects.

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 has 0% description coverage, so the description must explain the parameters. It does this thoroughly: group_id is identified as the group ID, name is described with its default behavior, and user_ids is explained as a complete replacement list with the removal consequence. This adds critical meaning beyond the raw schema types.

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 starts with 'Update a group,' a specific verb+resource combination that clearly states the tool's function. It further distinguishes itself from sibling tools by explicitly referencing add_user_to_group for the specific case of adding a single member without affecting others.

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 gives explicit usage guidance: 'To add one person without touching the rest, use add_user_to_group.' This tells the agent when to prefer an alternative tool, and implicitly when to use this tool (when replacing the full membership list is acceptable).

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