nexus_oauth_login

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

The description adds substantial behavior beyond the annotations: it discloses the use of PKCE S256 and random state, explains that bearer tokens take precedence over NEXUS_API_KEY, and describes the returned JSON structure. This gives the agent important security and workflow context that annotations alone do not convey. There is no contradiction with the annotations.

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 concise and well-structured: it front-loads the core purpose, then gives required security context, the follow-up step, and the return shape. Every sentence earns its place, and the 'Returns' block is clear and scannable.

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 two-parameter optional tool with a documented output schema, the description is complete. It covers the full OAuth flow from starting the flow, returning a URL, capturing the code, exchanging it, and understanding the resulting token precedence. An agent has enough context to invoke the tool and handle its output 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 description coverage is 100%, so the schema already documents both parameters well. The description does not add meaningful new meaning to the parameters themselves, and it does not need to because the schema covers scope defaults and redirect_uri override rules. This is the expected baseline for fully self-documenting schema.

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 specific verb and resource: 'Start the OAuth2 authorization-code flow' and 'returns the URL to open in a browser.' It also clearly distinguishes this from the related OAuth siblings by explaining that the returned code must be passed to nexus_oauth_exchange, making the tool's role in the flow unambiguous.

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 clear context for when to use this tool: to initiate OAuth login and obtain a browser URL. It explicitly points to the next step in the flow (nexus_oauth_exchange) and explains that bearer tokens unlock user-context mutations. However, it does not explicitly state when not to use it, such as checking nexus_oauth_status first or using nexus_oauth_refresh for existing tokens.

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