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

Annotations declare readOnlyHint=false (write) and destructiveHint=false (non-destructive), so the description doesn't need to restate that. The description adds critical behavioral context: it instructs to avoid sending government identifiers, birth dates, and card-processing details, and clarifies the constraint for ItemBasedExpenseLineDetail lines. These go beyond annotations and are valuable for safe usage.

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 main description is a single, front-loaded sentence that delivers the core purpose immediately. It's concise, though it could incorporate a brief usage-hint or differentiation. The entity parameter description is embedded in the schema, so the main description itself is efficient.

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 nested, complex parameter and no output schema, the description effectively covers the essential intent. The schema handles the detailed object structure. The description adds necessary guardrails about sensitive fields and line-detail conditions. No critical information for invoking the tool correctly seems missing.

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 baseline is 3. The entity parameter description in the schema already explains the object. The tool description adds meaning beyond the schema by warning about sensitive data and explaining the line-detail rule, which are not in the schema's generic description. This enriches the parameter understanding.

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?

Description clearly states the verb 'Create' and resource 'a bill' in 'QuickBooks Online.' This directly distinguishes it from siblings like create_bill_payment, create_purchase, and create_vendor_credit. The action is 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?

No explicit when-to-use guidance is provided. The description does not mention alternatives or conditions for choosing this tool over create_purchase/invoice. However, the name and the singular resource strongly imply this is for creating a bill, and the parameter guidance implies the required structure. Usage is implied but not explicitly differentiated.

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