create_subscription

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

Without any annotations, the description must disclose behavioral traits. It includes one useful note: 'Disabled in read-only mode,' which signals a precondition. However, it omits other behaviors like idempotency, authorization requirements, or side effects. This limited disclosure is adequate but not comprehensive.

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 extremely concise, consisting of two sentences: the purpose and a behavioral note. Both contribute directly, with no filler or redundancy. It is front-loaded and easily skimmable.

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?

While the output schema exists and parameters are fully described in the schema, the description lacks broader context such as prerequisites (e.g., package must exist), error scenarios, or idempotency. For a create operation with a nested object, this minimalism feels slightly under-specified, though it meets the basic requirement.

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%, so each parameter (product_id, package_name, subscription, regions_version) is already documented in the schema. The description adds no additional meaning about these parameters, but since the schema does the heavy lifting, a baseline score of 3 is appropriate.

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 clearly states 'Create a new subscription product in the catalog' with a specific verb and resource, effectively distinguishing it from sibling operations like patch_subscription (update) or get_subscription (retrieve). The action and scope are 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?

The description implies its use for creating subscriptions but offers no explicit guidance on when not to use it or which alternative to choose (e.g., create_in_app_product for non-subscription). The 'Catalog' context and verb 'Create' give some direction, but exclusions and comparisons are absent.

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