Get a customer

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: email is the only customer identifier, there is no customer-listing endpoint, and the returned record contains purchases, subscriptions, and order ids.

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?

Three sentences, each earning its place: the first defines the operation and result, the second connects the output to downstream tools, and the third gives routing guidance. No filler or redundancy.

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 simple read-only two-parameter tool with no output schema, the description fully explains what the caller gets back (purchases, subscriptions, order ids) and why it matters. It also covers the absence of a list-customers endpoint, which is essential context for an agent deciding how to use this tool.

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?

Input schema description coverage is 100%, so the baseline is 3. The description adds meaningful semantics by stating that email is the only way ThriveCart identifies a customer, reinforcing why the email parameter is required and how it should be interpreted beyond the schema's "exactly as they bought with" phrasing.

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 a specific verb and resource: "Get one customer's full record by email address," then enumerates the record contents (purchases, subscriptions, order ids). It is clearly distinguished from sibling tools like get_transactions by emphasizing that it retrieves a single customer by email.

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 explicitly states when to use an alternative: "there is no endpoint that lists customers, so use get_transactions when you need to see many at once." It also explains the tool's role as the source of order_ids for pause_subscription, resume_subscription, cancel_subscription, and refund_transaction, giving clear guidance on when this tool is required.

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