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

Annotations already cover the read-only safety profile, so the bar is lower; the description still adds useful context: the returned fields (type, status, total in smallest currency unit), newest-first ordering, page size of 100, and the API-key/auth requirement. This goes meaningfully beyond what the structured fields provide.

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?

Front-loaded with scope, then return shape, usage motivation, pagination, and auth in succession. Each sentence carries distinct information; slightly dense but nothing is wasted.

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?

No output schema exists, yet the description covers return fields, ordering, pagination mechanics, and auth requirements. An agent has everything needed to call it correctly and interpret results.

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 100%, so the baseline is 3, but the description adds real semantics: it explains the cursor round-trip (pass next_cursor back as cursor) and the 100-item page cap, which the schema alone does not convey. It also echoes the type enum values.

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?

States a specific verb (list) plus resource (credit notes), the scope (for a customer or an invoice), and the sort order (newest first). An agent can distinguish it from chargebee_create_credit_note and chargebee_get_invoice without opening a schema.

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?

Explicitly names the use case – checking whether an invoice was already credited before creating another credit note – which ties it directly to the sibling create action. It stops short of naming alternative tools for other scenarios, but the primary when-to-use is unambiguous.

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