Add one member to a Scaleway IAM Group

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

Annotations already indicate a write operation (readOnlyHint=false) and non-destructive (destructiveHint=false). The description adds value by stating that membership grants permissions immediately, existing members are preserved, and the tool refuses non-editable groups. No contradictions with annotations.

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?

Four sentences, each conveying distinct information: the core action, immediate effect, preservation of existing members, and refusal conditions. No filler words; front-loaded with the main purpose.

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 member addition tool with no output schema, the description covers the action, immediate effect, preservation, and refusal. The sibling tools are distinct enough. Minor gap: no mention of error handling or result status, but the description is sufficient for selection.

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 meaning by clarifying that both user_id and application_id can be provided simultaneously ('both may be given at once - it's not either/or'), which is not explicit in the parameter descriptions.

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 adds one User and/or one Application to a Group in a single call. It distinguishes from siblings by noting existing members are preserved and that it refuses non-editable groups, which differentiates it from set_group_members and remove_group_member.

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 context for when to use this tool: for adding a single user/application while preserving existing members. It also mentions refusal conditions (non-editable groups). However, it does not explicitly contrast with related tools like add_group_members (plural) or set_group_members, leaving some inference needed.

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