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

Annotations already declare readOnlyHint=true; the description adds the exact HTTP endpoint (GET /operators/{id}) and the returned fields (id, email, nickname, available). Since there is no output schema, listing the return payload provides useful behavioral context, though it stops short of covering error responses or authentication.

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?

Three short sentences, front-loaded with the action, with no filler. The API reference and return fields each earn their 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 get-by-id tool, the description covers purpose, endpoint, and return fields despite no output schema. Minor omissions like auth or not-found behavior are not essential for this scope, so it is nearly complete.

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%: the id parameter is already described as 'The operator id.' The description's mention of 'by id' and the endpoint path adds no new semantic detail beyond the schema. Baseline 3 applies because the schema carries the parameter documentation.

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?

States a specific verb ('Fetch'), a precise resource ('a single operator'), and disambiguates by ID ('by id'). Clarifies that 'operator' is a chat agent, distinguishing it from group/list/create/update 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?

The phrase 'Fetch a single operator by id' implies the intended use case and the need for an id, but it does not explicitly mention alternatives such as list_operators for multiple operators or update_operator for modifications. Usage context is present without exclusions or alternative routing.

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