list_credit_cards

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

Annotations already declare readOnlyHint=true, and description adds scope details (including available and total credit limit, Open Finance Brasil). However, it does not disclose any additional behavioral traits such as consent requirements, pagination, or rate limits; it also mentions a ctx arg not present in the schema.

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?

Description is fairly concise with an Args/Returns structure, but the Returns section redundantly restates the first sentence, and the ctx parameter adds an unnecessary line.

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 simple listing tool with readOnly annotation and output schema, the core purpose and parameters are covered. Missing is explicit guidance on when to choose this over sibling tools and any mention of consent/authorization context in Open Finance Brasil, leaving some ambiguity.

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?

With 0% schema description coverage, the description compensates by clarifying subject_id as User's CPF and bank as Identifier of the participating bank, matching schema's enum. However, the inclusion of ctx, which is not in the input schema, introduces some noise.

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?

Description uses specific verb 'Lists' with resource 'credit card accounts of a user at an institution participating in Open Finance Brasil', including limits. This clearly distinguishes it from sibling tools like get_credit_card_bills and list_accounts.

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 implies usage context (user at participating bank, listing credit card accounts) but does not explicitly state when to use this tool versus alternatives such as get_credit_card_bills or list_accounts, nor mention any exclusions or prerequisites like consent.

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