Search invoices

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 genuinely useful behavioral context beyond annotations: filters combine with AND, date bounds are inclusive, and the Balance field semantics for settled status. There is no contradiction with 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?

Four sentences, each earning its place: primary purpose, use cases, read-only declaration, filter semantics, and payment-status limitation. The most important information is front-loaded, and there is no repetition of schema content.

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 description covers purpose, when to use, filter behavior, a key limitation, and a hint about reading the Balance field in results. With 0 required parameters, 100% schema coverage, an output schema present, and annotations covering safety, nothing critical is missing for an agent to invoke this tool correctly.

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 fully documents all parameters. The description goes beyond the schema by clarifying how parameters interact ('Filters combine with AND'), stating the inclusive nature of date bounds (also in schema but reinforced), and explaining that payment status is not a filterable parameter. This adds interpretive value above the schema's per-field descriptions.

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 names a specific verb ('Find') and resource ('invoices') with three distinct filter dimensions: customer Id, transaction-date range, and document number. It also provides concrete use cases ('what a customer was billed in a period' and 'turn a document number into an invoice Id'), which distinguishes it from siblings like list_invoices, get_invoice, search_customers, and search_payments.

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 gives explicit use cases and an explicit when-not-to-use: 'Payment status cannot be filtered here: read the Balance field on each result.' However, it does not name an alternative sibling tool explicitly (e.g., 'use list_invoices for all invoices'), so it falls just short of full routing guidance.

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