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

The readOnlyHint annotation already signals a safe read operation, lowering the burden on the description. The description adds the HTTP endpoint ('GET /invoices'), which reinforces the read behavior, but it does not disclose pagination details, response shape, or rate-limit considerations.

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 compact and front-loaded, with the core action in the first sentence and supporting filter/API context immediately after. The only minor redundancy is that the first sentence essentially repeats the tool title.

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 list operation with four optional and fully documented parameters, the description is largely sufficient. The main gap is the absence of any note about the response format or pagination beyond what the offset parameter implies, but the schema and readOnlyHint cover most of the operational context.

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 schema has 100% description coverage and each parameter is already well-documented, so the baseline is 3. The description's mention of 'Filter by customer or status' paraphrases the existing customer_id and status properties without adding new semantic detail.

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 identifies the resource ('invoices') and action ('List'), and adds the key scoping dimensions: by customer or status. It does not explicitly contrast itself with sibling tools like chargebee_get_invoice or chargebee_list_transactions, so it stops short of full sibling differentiation.

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 implies when to use this tool: when a caller wants a list of invoices, optionally filtered by customer or status. However, it gives no explicit guidance about alternatives, such as using chargebee_get_invoice for a single invoice or chargebee_list_transactions for transaction-level detail.

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