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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the trailing 'Read-only' is largely redundant. The useful addition is describing what the statement reconciles ('net income, then operating, investing and financing activity, reconciled to the change in bank and cash balances'), but nothing is said about basis handling, currency fallback, or period requirements.

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 with no filler, and the core purpose is front-loaded. The redundant 'Read-only' tagline is the only wasted token.

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 shape need not be explained, and the description does describe report content. However, for a 5-parameter report tool with a semantically important basis enum and only 20% schema coverage, the absence of any parameter or period guidance leaves real gaps.

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 only 20% and the description adds no parameter meaning at all: basis (an enum whose ACCRUAL/CASH choice materially changes the report), currencyCode, startDate, endDate, and the nested companyId wrapper are all unaddressed. With low coverage the description is expected to compensate and does not.

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 ('returns the statement of cash flows for a period') and even lists the line-item structure the report contains. It distinguishes itself from generic report siblings by naming the cash-flow content, but never explicitly contrasts with accounting_get_balance_sheet, accounting_get_profit_and_loss, or accounting_get_statement, so the agent must infer the distinction.

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?

There is no guidance on when to choose this over the sibling financial statements, no prerequisites, and no exclusions. 'For a period' implies a date range is required but never states whether startDate/endDate are mandatory or how they interact.

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