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

Beyond the annotations, it discloses important hosting constraints, hidden UI delivery requirements, credential-handling rules, and fallback behavior when the card is unavailable. It does not explain the implications of readOnlyHint=false or idempotentHint=false, such as whether opening the card changes saved state.

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 action and primary purpose distinction are front-loaded, and the security constraint is clearly stated. It is compact overall, though the specialized terms reduce immediate clarity and could be tightened.

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 3-parameter tool with an output schema, it covers the critical usage and security caveats an agent needs before invocation. The main gap is that the required taskId parameter is left unexplained and sibling-tool routing is not addressed.

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 description reinforces the purpose enum semantics and adds the 'specifically requested' constraint for contact, but it does not explain taskId at all. Schema coverage is 67%, and the locale parameter is described only in the schema, so the description only partially compensates for the remaining gap.

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?

It states a specific verb (open) and resource (secure card / saved application form), and separates the two supported purposes. However, 'secure card' and 'hidden UI delivery' are jargon, and the description does not distinguish this tool from close siblings such as get_application or update_application.

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 explicitly covers when to use purpose=documents versus purpose=contact, including the stricter 'only when specifically requested' condition for contact. It does not name alternative sibling tools or give exclusions for the documents purpose, so a little routing guidance is missing.

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