merchant_ids_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 behavioral burden, and it discloses nothing: not that this is a mutating POST, not what gets created or destroyed, not whether existing merchant IDs conflict, and not what authorization is required. The only content is the route and a pointer to an external schema.

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, which is good, but it wastes its only sentence by duplicating the same route twice ('POST /v1/merchantIds (POST /v1/merchantIds)'). Under-specification rather than genuine conciseness.

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 mutation tool with zero annotations, no output schema, and a nested JSON:API body delegated to an external OpenAPI component, the description is far too thin. It should at minimum state what resource is created, the required envelope members, and any auth or side-effect expectations.

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% (the single 'body' property is described), so the baseline is 3 per the rubric. The description repeats the same pointer and hints that the body is a full JSON:API envelope, which adds marginal meaning, but the referenced components.schemas.MerchantIdCreateRequest is not expanded anywhere in the definition.

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 tool name as an HTTP route ('POST /v1/merchantIds') and adds nothing about what a merchant ID instance actually is or what creating one accomplishes. It is effectively a tautology against the name, and it does not distinguish itself from the many sibling create tools (e.g. pass_type_ids_create_instance, merchant_ids_update_instance).

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 whatsoever on when to call this versus merchant_ids_get_instance, merchant_ids_update_instance, or merchant_ids_delete_instance, nor any precondition, auth requirement, or idempotency note. An agent is left to infer everything from the name alone.

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