login_with_mfa

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action and input but does not explain success/failure behavior, session establishment, prerequisites, or side effects. For an authentication tool, this is a significant gap that could lead an agent to misuse or misinterpret the outcome.

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 three sentences, each serving a distinct purpose: stating what the tool does, when to use it, and how to provide the MFA code. Every sentence earns its place with no redundancy, making it concise and well-structured.

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 tool with one parameter and no output schema, the description covers the core use case: logging in with an MFA code. However, it lacks details about the login result, error handling, or whether the tool returns a session token. This is adequate for basic use but not fully complete for an agent that may need to handle failures or confirm success.

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 schema already fully describes the mfa_code parameter with the same wording as the description ('6-digit MFA code from authenticator app'). With 100% schema coverage, the description adds no extra semantic value beyond what the schema provides, so the baseline score of 3 is appropriate.

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 action (Login), the target system (Time Messenger), and the method (MFA code), making the tool's purpose unambiguous. It is easily distinguished from sibling tools, all of which are messaging/thread/channel operations, so there is no confusion with alternatives.

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 explicitly specifies when to use the tool: 'Use this when regular login requires MFA verification.' This provides a clear context, though it does not mention alternatives or exclusions. Since no sibling tool serves a login function, the guidance is sufficient without additional alternatives.

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