ClockNext: get customer plan

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

Annotations already declare readOnlyHint=true, so the description need not restate safety. It adds useful context that the plan is 'current active' and 'from their purchase,' revealing its dependency on purchase state. However, it does not disclose edge-case behavior (e.g., what happens if no active plan exists), and with openWorldHint true, behavior may vary. This is acceptable but not rich.

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 exactly two sentences: the first states the core function, the second provides a practical use case. It is front-loaded with the action and resource, and every word adds value. No redundant or fluff content.

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?

Given the tool's simplicity (one parameter, no output schema, read-only annotation), the description covers the essential aspects: what it does and when to use it. It does not explain the return format or edge cases, but the readOnlyHint and openWorldHint annotations help mitigate the need. The description is adequately complete for an agent to select and invoke the tool correctly.

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 input schema fully describes the single parameter 'id' as 'The ClockNext customer id.' The description adds only the word 'customer' in context, not additional meaning such as format, constraints, or usage examples. Since schema coverage is 100%, a baseline score of 3 is appropriate, and the description does not compensate beyond that.

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 the tool's function: 'Fetch a customer's current active plan (from their purchase).' It uses a specific verb and resource, and it distinguishes this from sibling tools like get_customer and get_plan by focusing on the customer's active plan. The additional use-case context ('confirm a customer is subscribed to the plan you expect') further clarifies its unique role.

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 a specific when-to-use scenario: 'Use it to confirm a customer is subscribed to the plan you expect before firing a test signal.' This offers clear guidance for appropriate use, though it does not explicitly mention alternatives or exclusion cases. The context is sufficient for most agents to differentiate it from related tools.

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