Sign in with Google

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

Annotations declare readOnlyHint=false and openWorldHint=true, but the description goes further with behavior the annotations cannot convey: the loopback callback means the flow only works when the user's browser is on the machine running the server, and the server receives the result automatically. It also discloses that no change occurs when credentials already exist. This is exactly the kind of context that prevents misuse.

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, front-loaded with the action and the returned artifact, then the procedural steps. Nothing is wasted, though the final conditional clause is slightly buried after the procedural instructions rather than merged with the earlier force mention.

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?

Although there is no output schema, the description explains the return value (authUrl) and what must be done with it. For a two-optional-parameter auth flow with annotations covering the safety profile, an agent has everything needed to call it correctly and handle the result.

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% and both parameters carry their own descriptions, so the schema does the heavy lifting. The description reinforces force's semantics ("unless force is true") but says nothing about openBrowser, adding no meaning beyond the schema. Baseline 3 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?

"Start the Google OAuth sign-in" is a specific verb+resource and immediately separates this from sign_out and get_auth_status in the sibling list. The description also names the artifact it produces (authUrl), so an agent knows exactly what the tool does before opening the schema.

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 states the full workflow: show the URL, wait for user confirmation, then call get_auth_status. It also names the alternative condition explicitly ("If already signed in, nothing happens unless force is true"), which tells the agent when a call is a no-op and how to override it.

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