set_default_bank

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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=true. The description adds genuinely new behavior: human approval is required, the account is verified before saving, and it happens only once. It does not explain why destructiveHint is true or what happens to a previously saved default account, which is the remaining gap.

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 tight sentences with zero filler; the core action is front-loaded and the approval prerequisite and demo constraints follow in priority order.

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 three-required-parameter mutation with no output schema and full schema coverage, the description covers the essential non-schema facts: verification, human approval, one-time nature, and demo constraints. It is nearly complete, lacking only what happens to a pre-existing default.

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 the schema already defines each field, including min/max lengths and the 10-digit pattern. The description only repeats demo values, adding no format or validation meaning beyond what the schema documents. 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?

The description states a concrete verb+resource: verify and save a default Nigerian bank account. It implies a one-time operation ('once'), which distinguishes it implicitly from the sibling get_default_bank. It does not explicitly name or contrast with that sibling, keeping it just short of a 5.

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?

It gives a prerequisite ('requires human approval through the MCP client') and demo-mode values, which is useful context, but it never states when to use this tool versus get_default_bank or when not to (e.g., if a default already exists). The set-vs-get distinction must be inferred from the name.

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