Railway MCP Server

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

No annotations are provided, so the description carries the full burden. It implies a read-only operation through 'List' and 'Viewing', but doesn't explicitly state if it's safe, requires specific permissions, or has rate limits. It adds some context about prerequisites and next steps, but lacks detailed behavioral traits like pagination or error handling.

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 with bullet points and arrows for easy scanning, front-loading the core purpose. Every section (Best for, Prerequisites, Next steps, Related) adds value without redundancy, making it efficient and readable.

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 (listing domains with 3 required parameters) and no annotations or output schema, the description is mostly complete. It covers purpose, usage, and relationships well, but could improve by adding details on return format or behavioral constraints. The high schema coverage helps compensate for gaps.

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 all three parameters (projectId, environmentId, serviceId). The description doesn't add any parameter-specific details beyond what the schema provides, such as explaining relationships between parameters. Baseline 3 is appropriate when the schema handles parameter documentation.

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 verb 'List' and the resource 'all domains (both service and custom) for a service', specifying the scope. It distinguishes from siblings like domain_create, domain_update, and domain_delete by focusing on listing rather than modifying domains.

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 usage guidance with 'Best for' sections (viewing endpoints, managing configurations, auditing settings), prerequisites (service_list), next steps (domain_create, domain_update), and related tools (service_info, tcp_proxy_list). This clearly indicates when to use this tool versus alternatives.

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