gcloud_auth_login

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

With no annotations, the description carries the full burden. It discloses key behavioral traits: it uses Application Default Credentials, it opens a browser for OAuth flow, and the optional 'force' parameter triggers re-authentication. This is sufficient for the agent to understand what will happen and the interactive nature of the tool.

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 two sentences, effectively front-loading the core purpose and the critical browser OAuth behavior. Every sentence adds value, though the second sentence could be slightly more precise about the interaction flow.

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?

Given the simplicity of this tool (one optional parameter, no output schema, clear purpose), the description is complete enough. It covers what the tool does, how it authenticates, and the interactive behavior. The only minor gap is that it doesn't specify that the tool may wait for browser completion or what to expect if run in a non-interactive environment.

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 100%, so the baseline is 3. The description adds no additional meaning beyond the schema for the 'force' parameter, but the schema already explains its purpose ('Force re-authentication even if already logged in'). The description does not provide extra usage context for the parameter.

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 specifies the verb 'Authenticate' and the resource 'Google Cloud using Application Default Credentials (ADC)', distinguishing it from siblings like gcloud_auth_list (lists accounts) and gcloud_auth_print_access_token (prints tokens). The purpose is well-defined.

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 implicitly communicates usage context ('authenticate with Google Cloud'), but provides no explicit guidance on when to use this tool versus alternatives, nor any exclusions or prerequisites. For instance, it doesn't mention that gcloud_auth_print_access_token or gcloud_auth_print_identity_token might be better for token-based scenarios without starting a browser flow.

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