verify_mfa

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

Annotations already indicate the tool is not read-only, not destructive, and idempotent. The description adds behavioral context by specifying the two operations (enrollment, step-up) but does not mention authentication requirements, rate limits, or side effects. It adds some value beyond annotations.

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 concise with two sentences, no unnecessary words. It front-loads the purpose in the first sentence and adds relevant context in the second. Every sentence serves a purpose.

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 tool with three parameters and no output schema, the description covers the core use cases but omits details like return values, error handling, or the result of successful verification. Given the complexity of MFA flows, it would benefit from mentioning what the tool returns or what happens on failure.

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 input schema describes code and challenge_id, but factor_id lacks a description. Schema coverage is 67%. The description does not add any parameter-specific details or clarify the parameters beyond the schema. It neither compensates for the missing factor_id description nor enhances understanding.

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's purpose: 'Verify MFA code to complete enrollment or step up to AAL2 session.' It specifies the verb (verify), resource (MFA code), and two distinct use cases, distinguishing it from sibling tools like verify_code or verify_email_otp.

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 explicit usage context: for enrollment completion or login step-up. It also notes that AAL2 is required for three specific developer key operations. While it doesn't list alternatives or when not to use, the context is clear enough to guide the agent.

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