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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, closed-world), so the description only needs to add context; it does, by stating the return payload past tense-style ("Returns the saved record with its SyncToken"), which signals the concurrency token needed for follow-up updates. It stops short of noting failure modes, duplicate-payment behavior, or permission requirements.

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?

Four short sentences, each front-loaded with a distinct fact: identity, definition, hard constraint, and return value. Nothing restates the tool name or the annotations, and the reader can stop after sentence two with a correct mental model.

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 create tool with no output schema, the description covers what gets created, the key restriction, and the return shape (record + SyncToken). It is nearly complete; only auth/prerequisite information (e.g., which connections or scopes are required) is absent, which is minor given the two-parameter surface.

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 entity parameter already documents LinkedTxn linking and prohibited data, so a 3 baseline applies. The description earns one extra point by documenting a field constraint not present in the schema ("ProcessPayment must be omitted or false"), which materially changes how the entity object must be built.

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+resource ("Create a payment in QuickBooks Online") and immediately narrows scope: it is an accounting record of a payment already received, not payment processing. This distinguishes it from siblings like create_bill_payment, create_credit_card_payment_txn, and create_sales_receipt without the agent needing to open another 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?

It gives a clear when-not ("Payment processing is not supported; ProcessPayment must be omitted or false"), which steers the agent away from a mistaken processing use. However, it never routes to the alternatives an agent would actually want here – create_bill_payment for vendor payments, create_sales_receipt for point-of-sale, or send_payment/invoice for collections – so usage is only implied.

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