Create Card

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

Annotations indicate mutation (readOnlyHint=false) and non-destructive (destructiveHint=false). The description adds that 'returned summaries redact the card number, code, and hidden fields,' which provides useful behavioral insight beyond annotations. This increases transparency.

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 consists of two focused sentences. The first states the purpose and resource, and the second adds constraints and behavioral notes. Every sentence is necessary and adds value without redundancy.

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?

The description is adequate for a creation tool with 13 parameters and no output schema. It covers the tool's scope (payment cards) and mentions redaction behavior. However, it does not specify what is returned upon creation (e.g., the item ID or full representation), which would enhance completeness.

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?

All 13 parameters have descriptions in the schema (100% coverage), so the baseline is 3. The description does not add new semantic context for parameters; it merely restates that custom fields and scoping are accepted. No additional meaning beyond what the schema provides.

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 'Create a payment card item' and lists specific fields (cardholder name, brand, number, expiry, code). It explicitly distinguishes from login credentials or notes, and the tool's name and title align with the purpose. The sibling list includes other creation tools (e.g., keychain_create_login, keychain_create_note), making the differentiation effective.

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 mentions usage for payment cards and not for login credentials or notes. It also notes that custom fields and folder/organization/collection scoping are accepted. While it doesn't explicitly name alternative tools, the sibling list provides context. A slightly higher score would require direct references to specific alternatives.

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