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

Annotations only indicate readOnlyHint=false and destructiveHint=false, so the description carries the burden of explaining that this is a mutation tool. It goes beyond the schema by stating that placeholder tokens are invalid, that the routeToken does not bypass preview or confirmation, and that the token remains valid across lookup, preview, and the permitted transaction. These are important behavioral constraints that prevent misuse and are not captured by annotations.

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 compact at two sentences and gets to the point quickly. The key constraint (requires an unconfirmed preview and explicit confirmation) is front-loaded. Some could argue the phrase 'unconfirmed preview' is slightly jargon-heavy, but overall it is efficient and free of fluff.

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 a tool with 20 parameters and no output schema, the description is too thin. It does not describe the preview step (how to obtain the preview), what the tool returns, or any side effects beyond the confirmation. An agent would need to inspect the schema and possibly related tools (like brc_route_request) to fully understand the workflow. This is a significant gap given the complexity of the operation.

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?

The schema has 55% description coverage (11 of 20 parameters have descriptions). The tool description does not add any parameter-level meaning; it only references routeToken and confirmCreate, which are already well-described in the schema. For the many parameters lacking descriptions (e.g., acCode, address, balance, sortCode, accountName, etc.), the description provides no clarification, so it does not compensate for the coverage gap.

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 clearly states the tool creates a bank account and explicitly differentiates it from other create tools by tying it to a preview/confirmation workflow. It names the specific resource (bank account) and the required confirmation mechanism, so an agent can distinguish it from brc_update_bank_account or other creation tools without ambiguity.

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 provides workflow context: it must be used after an unconfirmed preview, requires a valid routeToken from brc_route_request, and confirmCreate must be true only upon explicit user confirmation. It does not explicitly list alternative tools or say when not to use it, but the preview-and-confirm guidance gives a clear sense of the correct invocation sequence, which is enough for most agents.

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