get_account_balances

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It adds the key constraint that only cash accounts are supported and depots are not, which is valuable. However, it does not disclose return format, error behavior for invalid IDs, pagination, or whether it is read-only (though 'Get' implies it).

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 two sentences, front-loaded with the main purpose and followed by the key constraint. No redundancy or filler; every word earns its place.

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?

The description sufficiently explains the tool's scope for a 3-parameter, no-output-schema tool. It covers the account type restriction and date range. However, it leaves unspecified what the returned balance history looks like (e.g., daily balances, currency), which would be useful given no output schema.

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%, with each parameter (id, to, from) having clear descriptions. The tool description adds minimal extra parameter meaning beyond restating 'cash accounts' and 'date range', so the baseline of 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?

The description uses a specific verb ('Get') and resource ('balance history') with clear scope ('one or more cash accounts over a date range'). It also distinguishes itself from siblings by explicitly limiting to cash accounts (type '02_cash') and excluding depots, which sets it apart from tools like get_portfolio_valuation or list_accounts.

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 clearly states when the tool is applicable ('Works only with cash accounts... not depots'), giving a strong contextual constraint. It does not explicitly name alternative tools for depot balances, but the exclusion and sibling list imply when not to use it, so it earns a 4 rather than a 5.

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