bank_accounts_create

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

Annotations only flag non-readOnly, non-idempotent, non-destructive. The description adds the non-obvious side effects an agent needs: per-company IBAN uniqueness, a hard limit of one cash account per company, openingBalance locking after set, and demotion of an existing default account for the same currency when isDefault is true.

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?

Four tight sentences, front-loaded with the action, then the type-specific constraints, then the singleton cash rule, then the default-demotion side effect. No sentence is redundant with the schema or annotations.

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?

For an 8-param mutation with no output schema, the description covers the business invariants well, but it never says what the call returns (e.g., created account id) or whether any permission/role is required. Those are modest gaps rather than blockers.

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 100%, so the baseline is 3, but the description adds conditional meaning the schema states only per-field: IBAN required only for type=bank, and the default-demotion consequence of isDefault, which the schema's "Set as default account for this currency" does not convey. It leaves companyId override behavior and currency interaction to the schema.

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?

Opening sentence gives a precise verb+resource+scope: "Add a new bank account to the active company." The create semantics and the two account variants (bank vs cash) are unambiguous, so an agent can distinguish it from bank_accounts_update/list/delete without opening the 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?

The description clearly conditions usage on type: IBAN required for bank, optional for cash, and cash accounts exist to back POS/cash-register reports. It stops short of naming alternatives (e.g., bank_accounts_update for modifying an existing account) or stating exclusions, but the when-to-use context is explicit.

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