purchaseContract

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

No annotations are provided, so the description carries full burden of behavioral disclosure. It states 'purchase' but does not explain consequences such as payment processing, initiation of billing, whether the action is reversible, or whether it requires special permissions. For a mutation tool, this is a significant gap.

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 a single, clear sentence with no filler. It states the action and object efficiently, achieving the goal of conciseness despite being short.

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?

This is a mutation tool with 7 parameters, 3 required, no output schema, and no annotations. The description only says 'purchase a contract/membership', which does not explain return values, side effects, required permissions, or how this differs from other purchase-related tools. The schema covers parameter formats but does not address the tool's overall context, making the description inadequate for complex use.

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 86% (6 of 7 parameters have descriptions). The description itself adds no parameter-level detail, but the schema already provides meaningful descriptions for clientId, startDate, contractId, locationId, promotionCode, and clientSignature. The only parameter without a description is firstPaymentOccurs, but its enum values are self-explanatory. With high schema coverage, this meets the baseline.

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 'Purchase a contract/membership' clearly identifies the action (purchase) and the resource (contract/membership). It distinguishes itself from sibling tools like getContracts or getClientContracts, which are read-only, and checkoutShoppingCart, which handles broader cart checkout. The use of 'contract/membership' is slightly ambiguous but the parameter 'contractId' clarifies the target.

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 no guidance on when to use this tool versus alternatives (e.g., checkoutShoppingCart for purchases, addClientToClass for class enrollments). It does not mention prerequisites, required state (e.g., client must exist), or typical purchase scenarios. There is no 'when not to use' exclusion.

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