Add Group Member

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

The description adds a behavioral detail not present in annotations: 'Idempotent when the user is already a member.' This is valuable context beyond the readOnlyHint, destructiveHint, and idempotentHint flags. No contradiction with annotations is present.

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 and front-loads the primary action. Every word earns its place, with no filler or redundant information.

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 simple two-parameter tool with no output schema, the description is adequate but minimal. It covers the core operation and one behavioral nuance, but does not mention return values, error conditions, or permissions. Given the simplicity, this is acceptable but leaves gaps that an agent might need to infer.

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 has 0% description coverage, and the description does not explain the parameters userId and groupId beyond their names. The names provide some semantic hint, but the description fails to add any meaning such as formats, valid values, or relationships.

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 action 'Add a user to a group' with a specific verb and resource. It distinguishes from sibling tools like remove_group_member and list_group_members by specifying the 'add' operation. The idempotency note further clarifies the purpose.

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 context for using this tool is implied by its name and description, but there is no explicit guidance on when to use it versus alternatives. No exclusions or alternative tool references are provided, but the purpose is clear enough that an agent could infer usage.

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