create_payment_link

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions a constraint about mixing product types, which is useful, but fails to describe critical behaviors such as authentication needs, rate limits, what happens upon creation (e.g., link generation, storage), or error conditions. For a mutation tool with zero annotation coverage, 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 appropriately sized and front-loaded, starting with the core purpose. The bullet points for 'items' are well-structured, and the constraint about mixing products is clearly emphasized. However, the lack of complete parameter coverage or additional context slightly reduces efficiency.

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 complexity (7 parameters, mutation operation) and no annotations, the description is moderately complete. It explains the 'items' parameter well and includes a key constraint, but omits details on other parameters, behavioral traits, and usage context. The presence of an output schema mitigates some need to explain return values, but overall gaps remain.

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 description adds meaningful semantics for the 'items' parameter by detailing its structure (list of objects with product_id, quantity, coupons) and constraints (quantity ≥ 1, default 1). With 0% schema description coverage and 7 parameters, this partially compensates for the schema's lack of documentation, though it doesn't cover other parameters like 'name' or 'currency'.

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 purpose: 'Create a new payment / checkout link on Stream.' It specifies the verb ('Create') and resource ('payment / checkout link'), and the platform ('Stream'). However, it doesn't explicitly differentiate from sibling tools like 'create_invoice' or 'create_product', which would require a 5.

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 implied usage guidance by stating 'You **cannot** mix one-time and recurring products in the same link,' which hints at when not to use it. However, it lacks explicit guidance on when to choose this tool over alternatives like 'create_invoice' or 'create_product', and doesn't mention prerequisites or context for usage.

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