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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully structured. The description adds nothing beyond that: no statement of what is returned, whether results are scoped to the caller's workspace, or how 'active' is computed, so it contributes no behavioral context of its own.

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 core sentence is duplicated verbatim, which is pure waste, and what remains is a machine-generated operation ID plus a deferral link. There is no front-loaded statement of purpose or behavior to justify the length.

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?

With 0% schema coverage, an untyped free-form query object, and no output schema, the description had to carry the burden of explaining inputs and results. Instead it offers only the endpoint path and a redirect to describe_operation, leaving an agent unable to construct a correct call from this definition.

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% and the 'query' parameter is a free-form object with additionalProperties, so the schema gives the agent essentially nothing. The description does not name a single query key, filter, or pagination field, and only deflects to describe_operation, which is a pointer rather than parameter semantics.

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 restates the endpoint path 'GET /api/activity/users/active' twice and adds an operation ID, but never explains what an 'active user' means (active over what window, per what workspace), so the resource is only nominally identified. It gives no way to distinguish this from the many other activity/users endpoints among its siblings beyond the raw URL.

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 only guidance is 'describe_operation provides native request schemas', which tells the agent where to find a schema, not when to call this tool versus alternatives such as get_activity_f33beb4acdd4980fd012eb8c or get_activity_entity_by_entityType. No when-to-use, no exclusions, no prerequisites.

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