Add user to group

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

Annotations already cover the safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=true), so the description is not the sole carrier here. But it adds almost nothing beyond the raw endpoint path: it does not say whether admin privileges are required, whether the call errors when the user is already a member (relevant given idempotentHint=false), or what the response contains.

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 purpose sentence is front-loaded and efficient, but roughly half the description's length is consumed by a bare HTTP path that does little to help an agent select or invoke the tool. Nothing is verbose, but the second line earns little of its space.

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 two fully undocumented required parameters and no output schema, the definition leaves important gaps: permission requirements, behavior on duplicate membership, and failure modes are all absent. It identifies the operation but is thin relative to the calling risk.

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 0%, so both required parameters are undocumented in the schema, and the description does not compensate. It never clarifies whether user_id is a login name or numeric ID, or whether group_id is a display name or group ID — the exact ambiguity a caller is most likely to hit.

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 states a specific verb and resource ('Add one account to a group'), which is unambiguous on its own. It does not, however, name the obvious counterpart (nextcloud_remove_user_from_group) or scope the operation to differentiate it from user/group management siblings.

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?

There is no when-to-use guidance, no prerequisite statement, and no mention of alternatives such as nextcloud_list_group_members or nextcloud_remove_user_from_group. The agent must infer that this is the tool for membership assignment and that the user and group must already exist.

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