Get invoice

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond annotations: the read-only statement, the ok=false with status 404 on unknown Id, and the fact that the response includes the current SyncToken. This complements rather than merely repeats the annotations.

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 information-dense, with the core action and return contents in the first sentence, usage guidance in the second, and error/alternative-handling in the third. No sentence is wasted and the most important facts are front-loaded.

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?

Given the tool has a single parameter, a rich output schema, and annotations covering read-only and idempotent behavior, the description covers everything an agent needs: what it returns, why to call it, how to handle unknown IDs, and where to find IDs. The error case is explicitly documented, and siblings are referenced.

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%, and the schema itself already explains the parameter is the internal QuickBooks Id, not the DocNumber. The description adds context that the Id is what search_invoices, list_invoices, or create_invoice return, and that the SyncToken is needed by update/delete, which slightly enriches the parameter's purpose. This matches the baseline for high schema coverage with minor added value.

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 ('read'), a specific resource ('one invoice by QuickBooks Id'), and enumerates the returned fields (lines, totals, remaining balance, due date, SyncToken). It clearly differentiates from search_invoices and list_invoices, which are for finding invoices, making the tool's unique role unambiguous.

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 says when to use this tool: to check whether an invoice is still open and to get the SyncToken required by update_invoice and delete_invoice. It also tells the agent how to find an Id if unknown, naming search_invoices and list_invoices as alternatives, and explains the unknown-Id error behavior.

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