check_fines

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

With no annotations, the description supplies the safety profile: 'Returns' signals a read-only operation, and the 'including...' clause explains exactly what the total comprises. Minor edge cases like invalid member_id behavior are undocumented, but that's acceptable for a simple query.

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?

A single sentence that is front-loaded with the verb and object and contains no filler. Every clause earns its place by clarifying scope.

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 tool is simple, with one required parameter and an output schema present, so explaining return values isn't needed. The description states precisely what the returned total includes, which is enough for correct invocation.

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?

The schema covers only member_id's type and required status, and additional description coverage is zero. The description maps member_id to 'for a member,' adding slight semantic context, but provides no extra format or behavior details. For a single obvious parameter this is minimally sufficient.

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?

Clear verb 'Returns' with a specific resource, 'total outstanding fines for a member,' and scope, 'including overdue active loans and unpaid fines from returned books.' No sibling tool handles fines, so it is immediately distinguishable.

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 clearly frames when to use it: when a member's total fines are needed. It doesn't explicitly name alternative tools or exclusions, but the inclusion detail differentiates it from loan-returned siblings like get_loans.

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