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

With no annotations at all, the description carries the full burden of disclosing behavior. It does state it 'sets the JWT user active', which reveals the internal mechanism, but it omits critical details such as whether the operation is idempotent, what happens if the user is already active, or any side effects on existing sessions. For an admin mutation, this is insufficient.

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 a single, front-loaded sentence that starts with the '(Admin)' qualifier and immediately states the action. There is no fluff or repetition, every word earns its place.

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 one-parameter admin tool, the description provides the essential action and admin context. However, with no output schema and no annotations, it lacks information about the result of the operation, error conditions, or interaction with related account states. It is minimally adequate but has clear gaps.

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 a single 'email' parameter with no description (0% coverage). The description adds 'by email', clarifying that email is the lookup identifier, which is useful. However, it doesn't provide format expectations or edge-case behaviors, so it partially compensates for the schema gap but not fully.

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 a specific action: 'Activate a user's account' with the mechanism 'by email'. The verb 'activate' is precise and distinguishes this from siblings like deactivate_user and ban_user. The '(Admin)' prefix adds a clear access context.

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 '(Admin)' label implies this tool is for administrators, giving some usage context. However, there is no explicit guidance on when to prefer this over related tools (e.g., unban_user) or any exclusions. The when-to-use is only implied by the tool's name and purpose.

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