login_starbucks

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 ('Open browser') and the conditions under which it is used. It does not elaborate on possible side effects or post-conditions, but for a simple browser-opening tool, this is adequate transparency.

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 a single, concise sentence that is front-loaded with the action ('Open browser') and purpose. Every word earns its place, with no redundant or excessive 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?

Given the tool's simplicity (no parameters, no output schema) and its role as one step in a larger authentication flow (with sibling tools like complete_starbucks_login), the description provides enough context to understand what the tool does and when to invoke it. It could mention that it requires user interaction, but that is implied by 'login'.

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 input schema has zero parameters, and schema coverage is 100% (trivially). According to the rubric, baseline is 4 for zero parameters. The description does not need to explain parameters and does not add any, which is appropriate.

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 uses a specific verb 'Open browser' and clearly states the resource ('Starbucks login') and purpose ('first-time setup or to refresh expired session'). This distinguishes it from sibling tools like complete_starbucks_login or check_starbucks_auth by indicating it initiates the login flow by opening a browser.

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 explicitly states when to use the tool ('first-time setup or to refresh expired session'), providing clear context. It does not mention explicit exclusions or alternative tools, but the given context is sufficient for an agent to decide to use this tool over others.

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