auth_login

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

With no annotations, the description carries the behavioral disclosure burden. It mentions the browser-based OAuth flow and the side effect of setting a default project when project_id is provided. However, it omits details about credential persistence, user interaction (e.g., opening a browser window), or whether authentication modifies global GCP configuration.

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 succinct and front-loaded, with a main sentence followed by structured Args and Returns sections. There is no redundant or filler text; every sentence contributes useful information.

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 optional parameter and no output schema, the description adequately covers the action, the parameter's purpose, and the return status. It does not discuss error conditions or the need for an existing GCP account, but these are minor given the tool's simplicity.

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 'Args' section explains that project_id is optional and sets the default project after login, adding meaning beyond the schema's bare type and default. This compensates for the schema having no property descriptions (0% schema description coverage).

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 tool authenticates with Google Cloud Platform using browser-based OAuth flow, specifying a distinct verb and resource. It naturally stands apart from siblings like auth_list and auth_revoke by focusing on the login action.

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 minimal usage context (authentication) but no explicit guidance on when to use this tool versus alternatives like auth_list or auth_revoke, nor does it mention prerequisites or exclusions. The usage is implied rather than clearly instructed.

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