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

The description adds the Owner/Admin-only restriction, which is not present in the annotations. However, it does not disclose other behavioral traits such as whether the user must already exist, whether an invitation is pending or immediate, or any side effects beyond the basic mutation. The annotations already indicate a non-read, non-destructive operation, so the added permission context is valuable but not extensive.

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 extremely concise: two short sentences that convey the action and the permission requirement. Every word is necessary, and the 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?

Given the low complexity of the tool (two well-documented parameters) and the presence of an output schema, the description is largely sufficient for an agent to invoke the tool correctly. It covers the key permission gate but omits edge-case details like whether the user must not already be a member or how the invitation is delivered. These are not critical for basic invocation.

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 100%, with both parameters clearly described ('Argo user ID to invite' and 'Guild ID'). The tool description adds no additional parameter meaning beyond confirming the invite action, so the baseline of 3 for high schema coverage 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 clearly states the action ('Invite a user to join the guild') with a specific verb and resource. It is distinct from many sibling tools, though it does not explicitly differentiate from similar actions like add_co_gm or send_friend_request.

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 a permission context ('Owner/Admin only') which implies who should use it, but it does not explicitly state when to use this tool versus alternatives like send_friend_request or add_co_gm. The usage guidance is only implied by the action name and the permission note.

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