Check Orchyn Credits

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

Annotations already establish the safe read-only, idempotent profile, and the description adds useful operational context beyond them: the call is free and can be made anytime without worry. The description is fully consistent with readOnlyHint=true and adds no contradiction.

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 purpose is front-loaded in the first sentence and the cost/usage guidance is dense and useful. However, there is minor redundancy between 'before running other tools' and 'before a run of paid calls', plus a missing space after 'tools.Use', which reduces polish.

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 zero-parameter, read-only tool with an output schema present, the description covers everything an agent needs: what the tool checks, that it is free, and exactly when to invoke it. No critical information is missing.

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 tool has zero parameters and a 100% schema-coverage empty input schema, so the baseline of 4 applies. The description adds useful context about what the response reports (credit balance, billing URL, pack size), which compensates for the lack of a parameterized interface.

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?

Clearly states the resources the tool acts on (credit balance, billing URL, pack size) and uses a specific read-only verb, 'check', which distinguishes it from the sibling buy_orchyn_credits. An agent knows exactly what this does without opening the schema.

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?

Explicitly tells the agent when to call: anytime, and specifically before a run of paid calls to confirm balance coverage. It also removes cost hesitation by stating the call is free. It does not name an explicit when-not or point to the sibling buy tool, so it falls just short of a 5.

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