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

With no annotations, the description carries the full burden and does so well: it discloses the auth requirement (signed-in session), that a password is re-confirmed, that the call returns a fresh authenticator secret and otpauth:// URI, and crucially that no state changes until a later confirmation. It omits error/re-issue behavior if MFA is already enabled, which keeps it from a 5.

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?

Two tight sentences with zero filler; the prerequisite and the non-committal nature of the call are front-loaded before the return details. Every clause earns its place.

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?

No output schema exists, so the description correctly explains the return payload (secret + otpauth:// URI to scan as QR) and the follow-up step needed to finish. The only gap is what happens on repeat calls when MFA is already enabled.

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 single password parameter has 0% schema description coverage, so the description must compensate — and it does by explaining the password is used to confirm/re-authenticate the signed-in user before issuing a secret. It adds real meaning beyond the bare 'password' string field, though it doesn't state length or validation constraints.

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?

States a specific verb and resource ('start turning on two-step sign-in' / MFA setup) and explicitly frames the two-step flow, naming account_mfaEnable as the step that actually commits the change. An agent can distinguish this from account_mfaEnable, account_mfaDisable, and account_mfaRecoveryCodes without opening any schema.

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?

'Signed-in session only' gives an explicit prerequisite, and the closing sentence tells the agent this call alone does not complete enrollment — account.mfaEnable must confirm a code. It doesn't state when not to call it (e.g. if MFA is already enabled), so it falls short of full alternative/exclusion guidance.

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