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

Annotations only declare readOnlyHint=true and destructiveHint=false; the description adds the critical behavioral fact that this tool always returns 501 not_available, which no annotation conveys and which prevents wasted calls. It stops short of describing the response body or whether the endpoint may be populated on other gateways.

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?

Two short sentences, front-loaded with the unavailability fact and followed immediately by the alternative location. No filler.

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 stub with no output schema and one schema-documented parameter, the description supplies what an agent actually needs: that the call fails and where the data lives. It could be stronger by mapping the redirect to concrete sibling tool names or noting that the 'period' argument has no effect.

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% and the single 'period' parameter has an enum, so the schema fully documents it. The description never mentions the period parameter or clarifies that it is ignored, which counts against an otherwise schema-complete parameter.

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 plainly that this tool answers 501 not_available and that operator earnings history is not recorded on this gateway, so an agent immediately knows it is a stub rather than a working earnings endpoint. It does not name a sibling tool for the data, but the purpose is unambiguous.

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?

It gives a clear redirect: per-job payment state lives at GET /api/jobs/:jobId/execution, which implies the agent should use the job/execution tool instead. It does not cite the sibling tool by name (e.g. get_job / get_job_telemetry), so the routing requires an extra inference step.

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