google_add_account

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

With no annotations, the description carries the full burden. It discloses the key behavior: returns a URL, requires user interaction in a browser, and needs a follow-up call to complete authentication. It also lists the permission tiers. It doesn't mention potential failures or whether the tool is non-destructive, but for an OAuth initiation, the core flow is well covered.

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 sentences cover purpose, the two-step flow, and the available tiers. No redundant content; it's front-loaded and every sentence earns its place.

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 tool's complexity (OAuth flow) and lack of output schema, the description explains the return value (authorization URL) and the required next step. It also lists all permission tiers. It doesn't cover edge cases like account existence or revocation, but it is sufficiently complete for an agent to invoke correctly.

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% (both parameters have descriptions and enums). The description adds the default value 'mail_readonly (default)', which is not in the schema, and clarifies the difference between scopeTier and scopeTiers. This goes beyond schema alone, warranting a 4.

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 clear verb+resource: 'Add a new Google account via OAuth.' It distinguishes this from siblings by explaining it initiates OAuth and returns an authorization URL, which is unique among the Google account tools. The tier list further clarifies scope.

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?

It explicitly tells the agent to show the returned URL to the user and to use google_check_pending_auth after authorization, providing a clear workflow. However, it doesn't explicitly mention when not to use this tool or alternatives like reauth for existing accounts, so it falls short of a 5.

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