List virtual passkeys for a browser session, filtering by relying party ID or credential ID. Private key material is omitted unless explicitly requested.
List virtual passkeys, optionally filtered by rpId or credential id. Private keys are omitted unless includePrivateKey=true.
| Name | Required | Description | Default |
|---|---|---|---|
| id | No | Base64url credential id. | |
| rpId | No | ||
| includePrivateKey | No | Return private key material. Default false. |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly warns that private keys are omitted unless includePrivateKey=true, which is important safety-sensitive behavior. It does not describe the return format, but that is less critical for a simple listing tool.
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 is two concise sentences with no wasted words. The core action and filters are front-loaded, followed immediately by the important privacy-related default behavior.
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 optional-filter listing tool with no required parameters and no output schema, the description provides sufficient detail: what is listed, how it can be filtered, and the sensitive private-key default. It is complete enough for an agent to invoke correctly without further guidance.
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?
Schema coverage is 67%, with rpId lacking a schema description. The description adds meaningful context by stating that results can be filtered by rpId or credential id, and clarifies that includePrivateKey controls private-key material exposure. This compensates for the schema 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?
The description uses a specific verb 'List' with a clear resource 'virtual passkeys' and names the optional filters (rpId or credential id). This clearly distinguishes it from sibling tools like browser_passkey_create, browser_passkey_install, and browser_passkey_delete.
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 makes the tool's purpose and optional filtering context clear. It does not explicitly state when to use it versus alternatives, but the verb 'List' and the sibling names make the intended use unambiguous enough for an agent to select it for read-only passkey enumeration.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.