configure_api_token

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It effectively describes the tool's purpose (authentication configuration), when it's needed ('only needed if not set in environment variables'), and hints at its mutating nature ('Configure', 'Token updates'), which is appropriate. However, it lacks details on potential side effects (e.g., token persistence, error handling) or response format, leaving some behavioral aspects unclear.

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 well-structured and front-loaded with the core purpose, followed by bullet points for best uses, exclusions, and related tools. Every sentence earns its place by providing clear, actionable information without redundancy or fluff, making it highly efficient and easy to parse.

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 (simple authentication setup with one parameter), no annotations, and no output schema, the description is largely complete. It covers purpose, usage guidelines, and exclusions effectively. However, it lacks details on behavioral outcomes (e.g., what happens after configuration, error scenarios), which would enhance completeness for a tool with no structured output information.

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%, with the parameter 'token' fully documented in the schema. The description does not add any additional meaning or context beyond what the schema provides (e.g., it doesn't explain token format, security implications, or validation rules). With high schema coverage, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't detract.

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 specific action ('Configure the Railway API token for authentication') and resource ('Railway API token'), distinguishing it from all sibling tools which focus on projects, services, deployments, domains, variables, volumes, etc. The purpose is unambiguous and directly addresses authentication setup rather than operational tasks.

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 provides explicit guidance on when to use this tool ('Initial setup', 'Token updates', 'Authentication configuration') and when not to use it ('Not for: Project configuration, Service settings, Environment variables'). It also suggests next steps ('project_list, service_list') and related tools ('project_create'), offering clear alternatives and context for usage.

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