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

Annotations only declare readOnlyHint and openWorldHint=false, but the description goes well beyond that: it enumerates the three possible statuses, defines outstandingBalance as NET (open invoices less unmatched payments, can be zero or negative when paid ahead), and warns against calling a negative balance a debt. That is precisely the extra context an agent needs before speaking a number to a user.

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?

Front-loaded with the core purpose and each subsequent clause carries distinct operational detail, but the dense nesting of parentheticals (the credit-check-in-chat aside, the balance arithmetic) makes it heavier than it needs to be. Nothing is wasted, though.

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?

There is no output schema, so the description must describe returns — and it does, covering all three statuses and the fields returned for each (id, outstandingBalance, candidates, nearMiss). Nothing needed to call or interpret it is 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 0% for the single param, so the description must carry the load. It conveys that the input is a customer name as written/abbreviated and that prefix and near-miss matching are attempted, which adds real meaning beyond the bare string type.

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 (Resolve) and resource (a customer name for an invoice draft) plus the scope (against this company's real customers). An agent can distinguish it from resolve_vendor/resolve_product by the resource alone without opening any 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?

Explicit routing guidance for each outcome: ask the user which candidate when ambiguous, treat nearMiss as likely shorthand, only file as new on user confirmation, and never guess. This is genuine when/when-not guidance, not inference.

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