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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds one useful behavioral detail: it returns the saved record with its SyncToken, which matters for subsequent updates and deletes. However, it does not disclose validation errors, duplicate handling, 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?

The description is two short, front-loaded sentences with no redundant or filler content. The core operation is stated immediately, followed by the return value detail, which is efficient and easy to parse.

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's complexity (nested entity object) and the absence of an output schema, the description partially compensates by stating that the saved record and its SyncToken are returned. Yet it still lacks guidance on usage versus sibling create tools and omits behavioral context such as validation or side effects. With rich schema and annotations, this is adequate but with clear gaps.

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%, so the schema itself documents both parameters thoroughly, including the complex entity object and company selection. The description adds no parameter-level meaning beyond what the schema provides, making the baseline 3 appropriate.

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 states a precise verb and resource: 'Create a bill in QuickBooks Online.' This clearly identifies the operation, but it does not differentiate the tool from other create operations like create_invoice, create_purchase_order, or create_journal_entry, so sibling ambiguity remains.

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 offers no guidance on when to use this tool versus alternatives such as create_invoice or create_purchase_order. It also omits prerequisites or context about when a bill is appropriate, leaving usage entirely implicit from the tool name.

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