skypilot_api_login

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

Annotations only declare destructiveHint=false, so the description carries most of the behavioral burden. It usefully discloses a significant side effect ('Sets the endpoint globally so all subsequent SkyPilot calls use it') and the OAuth2 re-authentication semantics of relogin, which the annotations do not convey. It omits idempotency behavior and what happens when already logged in, keeping it below 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?

Three tight sentences, front-loaded with the core action before the side effect and the parameter hint. No filler, though the third sentence is somewhat tacked on rather than integrated.

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?

An output schema exists, so return values need not be described. However, with 0% schema coverage across three parameters and a global-state mutation, the definition leaves the agent unsure how endpoint and service_account_token interact with the login flow, which is a real gap for a tool whose whole purpose is establishing auth context.

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 description coverage is 0%, so the description must compensate, but it only explains one of three parameters (relogin). Neither endpoint nor service_account_token is clarified — e.g., what endpoint means when null, or how a service account token replaces interactive OAuth2 login.

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 first sentence gives a specific verb+resource ('Log in to a remote SkyPilot API server'), which is unambiguous against siblings like skypilot_api_logout, skypilot_api_status, and skypilot_api_info. It stops short of explicitly contrasting itself with those siblings, so it lands just under the top tier.

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?

Usage is implied rather than stated: the agent can infer this must precede server calls, and the description gives one conditional ('Set relogin=True to force re-authentication'). There is no explicit when-to-use/when-not guidance, no prerequisites (e.g., whether a server must be started first), and no mention of the logout counterpart.

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