List all cards

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

The readOnlyHint annotation already establishes this as a safe read, so the description need not restate it. It does add that results are scoped to an account holder, but says nothing about pagination, result size, or whether cards are returned for all holders under the credentials — a real ambiguity given the phrase "for an account holder".

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?

A single front-loaded sentence with no filler or redundancy. Nothing is wasted and the resource comes first.

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?

With an output schema covering return values and a readOnlyHint covering safety, the description only needs to state purpose and scope, which it largely does. The remaining gap is the unresolved question of which account holder's cards are returned.

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?

There are zero input parameters and schema coverage is 100%, so the baseline is 4. The phrase "for an account holder" implies the holder is derived from auth context rather than passed in, which is consistent with the empty schema, though it could momentarily make an agent look for a holder parameter.

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 gives a specific verb and resource ("Get all the cards") and adds scope ("for an account holder"), which is enough to separate it from card_lock_update and the payee/savings siblings. It stops short of naming any sibling or contrasting behavior, so it is clear but not differentiating.

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: an agent can infer you call this to enumerate cards, but the description states no when-to-use condition, no alternatives (e.g., card_lock_update for state changes), and no prerequisites. Adequate for a zero-parameter list tool, but nothing explicit.

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