Create subscription price

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

Annotations already indicate a mutation (readOnlyHint=false). The description adds valuable behavioral context by disclosing the 409 ENTITY_ERROR.RELATIONSHIP.INVALID error when availability is not set, which is beyond the annotation's boolean hints. It does not contradict annotations and makes the failure mode predictable.

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 three sentences, each with a distinct purpose: stating the core operation, warning about a prerequisite, and providing ID sourcing guidance. Every sentence earns its place with no redundancy or 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?

The description covers the critical dependency (availability), a specific error code, and valid ID sourcing, which are essential for correct use. Without an output schema, it doesn't detail the response shape, but for a create operation with well-documented parameters and annotations, the provided context is sufficient and complete.

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 the baseline is 3. The description adds cross-tool semantics for territoryId, explaining it must match the filter.territory used in list-subscription-price-points, and clarifies the 'optionally territory' scope. This enriches the parameter meaning beyond the schema's individual field descriptions.

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 opens with 'Attach a price to a subscription', a specific verb-resource pair that clearly states the tool's function. It further distinguishes itself from sibling tools like create-subscription-availability and list-subscription-price-points by explicitly referencing them as prerequisites, making the purpose 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 provides explicit guidance on when to use this tool: after setting subscription availability, warning that a 409 error occurs otherwise. It also names the specific sibling tool create-subscription-availability for that prerequisite step and instructs using list-subscription-price-points for valid IDs, including the territoryId matching requirement.

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