bank_balances

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine behavioral value beyond them by warning that date arguments are rejected and that only current balances (not historical) are returned. It does not mention auth requirements or rate limits, which keeps it from a 5.

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, zero filler, with the scope constraint and read-only nature front-loaded before the routing guidance. Every clause 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?

An output schema already exists, so return values need no explanation. Combined with the read-only annotation and the explicit sibling routing, the definition gives an agent everything needed to select and invoke this tool 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 coverage is 0% and the two date parameters have no descriptions in the schema. The description partially compensates by warning that dates are rejected, which is important disambiguation, but it never explains the expected format or behavior of from_date/to_date, leaving the presence of those params in the schema unexplained.

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 (current bank/cash balances) with an explicit scope qualifier ('CURRENT ... only') and marks it read-only. It is immediately distinguishable from balance_sheet, trial_balance, and bank_activity without opening any 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?

Explicitly names the alternative path for drill-down ('use list_records/get_record on bank_accounts') and states the exclusion ('rejects dates'). An agent knows both when to call this tool and when to route elsewhere.

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