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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation risk is covered by structured data. The description adds only the Id/SyncToken prerequisite; richer behaviors like sparse updates, line replacement, and cleared fields live in the input schema rather than in the tool description itself.

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, front-loaded sentence that states the operation and its key prerequisite with no filler. It is appropriately sized for a tool whose input schema carries the detailed parameter semantics.

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?

The schema descriptions and annotations together make the tool callable with confidence, covering required fields, protected data, and destructive intent. The main gap is the lack of an output schema or return-value information, but that is minor for a straightforward update operation.

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 entity parameter is richly documented: required Id/SyncToken, forbidden sensitive fields, sparse-by-default behavior, Line array replacement semantics, and the effect of sparse:false. The description itself merely echoes the Id/SyncToken requirement, so the schema does the heavy lifting.

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 verb ('Update'), the resource ('existing sales receipt'), and the system ('QuickBooks Online'). The phrase 'existing' and the Id/SyncToken requirement distinguish this from create, delete, void, and send operations on the same document type.

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 it: when modifying an already-created sales receipt and when you have the current Id and SyncToken. However, it does not explicitly name alternatives or state when not to use it versus create_sales_receipt, void_sales_receipt, delete_sales_receipt, or search_sales_receipts.

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