passkey_login_options

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

No annotations are provided, so the description must fully convey behavioral traits. It fails to disclose what 'create options' entails (e.g., generating a challenge, ephemeral data), whether it is a read-only or mutating operation, or what side effects occur.

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 a single, concise sentence (13 words) with no wasted words. It effectively conveys the core purpose without extraneous information.

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?

Given the absence of an output schema, the description should explain what the tool returns (e.g., a challenge, options object) and how it relates to subsequent steps like passkey_login_verify. It does not, leaving the agent without critical context for a complete workflow.

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 100%, reducing the need for additional parameter descriptions. The description adds one useful detail: 'Optional email hint. Does not expose allowCredentials,' which provides behavioral context beyond the schema. This incremental value justifies a baseline 3.

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 the tool creates WebAuthn passkey login options for a project app origin. It uses a specific verb (create) and resource (login options), and distinguishes itself from sibling tools like passkey_register_options and passkey_login_verify.

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 provides no guidance on when to use this tool versus alternatives. It does not mention the need to call this before passkey_login_verify or explain its role in the login flow, leaving the agent without context for proper usage.

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