Log in (customer)

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

With no annotations provided, the description carries the behavioral disclosure burden. It reveals that credentials are stored server-side and never returned, and that failed authentication returns 'success:false with a reason.' This adds meaningful behavioral context beyond the operation name.

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?

Three concise sentences, each earning its place: the core action, the downstream use of the session_id, and the error behavior. Information is front-loaded and there is no redundancy.

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?

The description covers the essential return values (session_id, success:false with reason) despite the lack of an output schema, and ties the tool to downstream callers. It does not specify session expiration or exact response structure, but for a simple login tool this is largely sufficient.

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%, so the parameter descriptions already document email and password. The tool description adds minimal semantic value, mentioning that authentication uses email and password and that the credential is not returned, but this does not go beyond the schema baseline.

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 states a specific verb ('Authenticate') and resource ('a customer'), and clarifies the purpose by explaining the returned session_id is used with get_customer and get_order_status. This clearly differentiates login from the read-oriented sibling tools.

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 gives clear context by indicating that login should happen before using get_customer and get_order_status, and hints at the failure mode for bad credentials. It does not explicitly mention when not to use it or name alternatives, but the intended use is clear.

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