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

Goes well beyond the readOnly/destructive annotations: it discloses the data provenance (real bank balances + real invoices plus a projected settlement component with band and accuracy), that trade direction is a mechanical consequence of the gap sign rather than a recommendation, and the meaning of sufficient_history=false. This is exactly the behavioral context annotations cannot carry.

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 identity before listing capabilities, and nearly every clause carries distinct information. It is a dense single paragraph, though, and the middle run-on enumerating answers slightly taxes readability.

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?

An output schema exists, so return values need not be explained, yet the description still names key output concepts (can_self_fund, base_funding_shortfall, sufficient_history) and the data sources. For a 2-param, read-only forecast tool, nothing an agent needs to call it correctly 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 description coverage is 100%, so the schema already documents both currency and horizon_weeks (including the 1-26 range and default). The description reinforces the per-currency/base-currency framing but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 and resource (a per-currency running cash-balance funding forecast) and explicitly scopes it against siblings by noting it INCLUDES base currency 'which the FX-exposure tools deliberately exclude'. An agent can distinguish it from get_fx_exposure without opening a 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?

Clearly frames the questions it answers (will the user hold units to settle payables/receivables, first date each currency runs short) and routes away from FX-exposure tools. However, it does not explicitly contrast with other nearby siblings like get_cashflow_forecast or get_cash_position, so the when-to-use is clear but not fully disambiguated.

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