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

Annotations already provide readOnlyHint=true, and the description is consistent with that. The description adds the API endpoint format but does not disclose error behavior, authentication requirements, or response characteristics. With annotations covering the safety profile, the description provides only modest additional behavioral context.

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, compact sentence that front-loads the core function and then adds the precise API reference. Every word contributes value, with no redundancy or filler.

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 single-parameter read operation with readOnlyHint=true, the description gives enough context for an agent to select and invoke the tool. It lacks explicit details about not-found behavior or return format, but these are less critical given the tool's low complexity and the absence of an output schema.

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 100%, and the parameter is already well documented as 'Chargebee customer id'. The description reinforces that the customer is retrieved by id but does not add meaningful detail beyond the schema, such as format requirements or value constraints.

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 'Retrieve a single customer by id', specifying both the action and the resource. It also provides the exact Chargebee API endpoint pattern, which distinguishes it from sibling tools like chargebee_list_customers, chargebee_create_customer, and chargebee_update_customer.

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 makes the usage context clear: use this when you have a specific customer_id and need that one customer. It does not explicitly name alternatives or state when not to use it, but the distinction from list/create/update siblings is reasonably implied.

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