List supported banks

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds a genuinely new behavioral fact beyond the annotations: the list is cached for an hour, which tells the agent results may be stale and that repeated calls are cheap. It does not mention ordering or full page-size behavior, but for a closed static list that is minor.

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 short sentences, the purpose front-loaded, followed by the practical payoff (which field to reuse) and the caching caveat. No redundant phrasing or filler.

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 zero-parameter, annotation-rich lookup with no output schema, the description covers purpose, the key returned field, and a caching caveat. It stops short of describing the other returned attributes (e.g., the human-readable bank name) or the ordering of results, which is the only remaining gap.

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 tool takes zero parameters, so the baseline is 4. The description goes slightly beyond by explaining that the returned 'code' field is what should be passed as 'bank_code' elsewhere, adding downstream meaning rather than restating 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?

States a specific verb and resource ('List supported banks') and immediately qualifies the scope: the banks you can send transfers to. No sibling tool in the list does bank enumeration, so the resource is unambiguous and the purpose is fully identifiable.

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?

Usage is only implied: the agent can infer it should call this before create_transfer to obtain a bank_code. There is no explicit statement of when to use this versus alternatives (e.g., resolve_account for resolving a specific account, or list_sandbox_test_values for test data) and no exclusions or prerequisites.

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