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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the data comes from the ledger, it requires the user's GetAccountED sign-in, and the user is prompted to sign in the first time. It does not discuss latency or data freshness beyond the period default.

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 purpose, followed by a compact enumeration and two short supporting sentences on defaults and auth. The list is long but each item is a distinct data category that earns its place; no filler wording.

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?

With no output schema, the description carries the burden of describing return contents, and it does so by enumerating the reported figures. Auth requirements and period defaults are covered. Minor gap: it does not indicate the shape/grouping of the response or whether figures are per-currency, but for a read-only overview this is close to complete.

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 all three parameters (from, to, business_id) are already documented with formats and defaults. The description only restates the default period, adding no syntax or edge-case meaning beyond the schema. 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 resource ('snapshot of the business's books for a period') and enumerates exactly what it contains: income, expenses, profit, bank balances, debtors/creditors, VAT position, unreconciled bank lines and missing slips. This enumeration implicitly separates it from narrower siblings like accounting_profit_and_loss, accounting_balance_sheet and accounting_reconciliation_status by making clear it is the aggregate view.

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 default period ('this month so far') and the sign-in prerequisite give useful context for calling it, but there is no explicit when-to-use guidance or named alternative (e.g. 'use accounting_profit_and_loss for a detailed P&L'). Usage is implied rather than stated.

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