subscription_offer_code_custom_codes_create_instance

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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it discloses nothing: no auth requirements, no statement about what is created or whether it is reversible, no validation or error behavior, and no note that this is a write operation with side effects. Pointing at an OpenAPI schema is not a substitute for behavioral context.

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 short and front-loads the endpoint, which is good, but it wastes space by repeating the path verbatim twice inside parentheses and echoing the schema reference already present in the input schema. It is brief without being informative.

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 create/mutation tool with no annotations, no output schema, and a nested JSON:API body whose real shape lives in an external component, the description leaves critical gaps: what fields are required, what the response contains, and what happens on conflict. It defers entirely to external documentation rather than making the tool callable on its own.

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 there is a single body parameter, so the schema already names the request component. The description adds only the note that the body is a 'full JSON:API envelope', a marginal hint beyond the schema's own reference, so the baseline of 3 applies.

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 simply restates the HTTP method and URL path (POST /v1/subscriptionOfferCodeCustomCodes) that the tool name already encodes, giving no human-readable explanation of what a custom code is or what creating one accomplishes. It does not distinguish this tool from siblings like subscription_offer_code_one_time_use_codes_create_instance or in_app_purchase_offer_code_custom_codes_create_instance. This is effectively a tautology of the name.

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?

There is no guidance on when to use this tool, what prerequisites exist (e.g., an existing offer code parent), or how it differs from the one-time-use-code and get/update siblings in the same family. The agent is left to infer everything from the endpoint name.

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