Real-Time Balances

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

Discloses key behaviors: fresh fetch per call with caching, sign convention for credit/loan balances, fallback to cached data with note. No annotation contradictions.

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?

Two sentences covering purpose, source, caching, sign convention, error handling, and return structure. No wasted words.

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 zero parameters, no output schema, the description provides a detailed return structure and error handling. Fully adequate for an agent to use 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?

No parameters; description explicitly notes 'No args.' Schema coverage is 100%, so description adds value by confirming no input needed.

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?

Clearly states it returns live per-account balances and net worth via SimpleFIN. Differentiates from sibling tools by specifying real-time nature and caching behavior. No ambiguity.

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?

States prerequisite (requires finance_link_bank first) and fallback behavior when live fetch fails. Could explicitly mention when not to use among siblings, but overall clear.

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