create_customer

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

No annotations are provided, so the description carries the full burden. It claims 'No side effects' and 'without modifying external systems,' yet creating a Stripe customer inherently modifies an external system via the Stripe API. It also claims 'No authentication required for basic usage' while the schema includes an api_key parameter. The description contradicts the tool's fundamental nature as a side-effecting, authenticated external API call.

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 organized into labeled sections, which is structurally sound, but large portions are filled with irrelevant content about analysis/classification that belongs to a different tool. These misleading blocks should be removed entirely; the useful content is only the first line and parameter list.

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?

For a mutation tool hitting an external service, the description should disclose auth requirements (api_key), side effects, rate limits, and return behavior. It instead claims the opposite of the truth — no side effects and no auth. It also fails to describe what the created customer returns. The definition is seriously inadequate and misleading for the actual operation.

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 coverage is 0%, so the description must document parameters. It covers name, email, and metadata with reasonable examples, but omits the api_key parameter entirely even though it is present in the schema and relevant to the tool's true behavior. This leaves the agent uninformed about one of the four parameters.

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 opening line 'Create a new Stripe customer' states a clear verb+resource, but the Behavior section immediately contradicts it by claiming the tool 'generates structured output without modifying external systems' and frames it as a 'structured analysis or classification' tool. An agent reading the full description would be confused about whether this creates a customer or performs analysis.

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 'When to use' section suggests this tool is for 'structured analysis or classification of inputs against established frameworks' — completely unrelated to creating a Stripe customer. The 'When NOT to use' warning about production decision-making is also irrelevant to a customer-creation operation. This guidance actively misleads rather than helps.

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