cash_flow

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

Beyond the readOnlyHint annotation, the description discloses important behavioral details: default account scope, the filtering of internal transfers, the semantic difference between net cash flow and gross movement, and the effect of include_transfers. It also describes the group_by output shape. This substantially exceeds what annotations alone convey and contains no contradiction.

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 description is front-loaded with purpose and scope, then organized into clear behavioral notes and an Args block. Every sentence adds information—scope exclusions, transfer filtering rationale, and parameter details—without filler or repetition. It is appropriately detailed for a tool with nuanced behavior.

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?

For a tool with five parameters, two required, and meaningful default-scope behavior, the description covers the essential decision points: what counts as cash flow, what is excluded, how to include transfers, and how grouping changes output. The presence of an output schema means return-value documentation is not required here. An agent has enough context to call it 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 0%, so all parameter meaning must come from the description. It thoroughly explains every parameter: date formats, account default behavior, include_transfers semantics for both values, and group_by allowed values plus output format. This fully compensates for the bare schema.

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 opens with a specific verb and resource: 'Calculate cash flow (inflows and outflows) for a period.' It clearly distinguishes itself from siblings by defining the default scope as BANK and CASH accounts and explicitly contrasting with balance_sheet for credit-card and investment movements. This leaves no ambiguity about what the tool computes.

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 when-to-use guidance and names an alternative: credit-card and investment movements are not cash flow and should use balance_sheet. It also clarifies when to pass include_transfers=true, such as when reconciling against a bank statement, and explains the default filtering philosophy. This is model usage guidance.

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