Railway MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It hints at creation behavior ('Create a new domain') and mentions prerequisites, but lacks details on permissions, rate limits, or error handling. However, it adds useful context like HTTPS endpoints and Railway's automatic generation, which compensates partially for the annotation gap.

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 icons, making it easy to scan. However, it includes some redundancy (e.g., repeating 'railway will generate one for you' in the schema) and could be more front-loaded; the core purpose is clear but buried slightly in formatting.

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 complexity of a creation tool with no annotations or output schema, the description does a good job covering usage, alternatives, and prerequisites. It lacks details on return values or error cases, but the structured guidance and clear purpose make it mostly complete for agent use.

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 5 parameters thoroughly. The description does not add any parameter-specific semantics beyond what the schema provides, such as explaining the interaction between domain and suffix. This meets the baseline of 3 for high schema coverage.

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 ('Create a new domain') and resource ('for a service'), distinguishing it from siblings like domain_update, domain_list, and tcp_proxy_create. The title is null, making the description's clarity even more critical, and it successfully fulfills this role.

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 with 'Best for' and 'Not for' sections, naming alternatives (tcp_proxy_create), prerequisites (service_list, domain_check), next steps (domain_update), and related tools (service_info, domain_list). This comprehensive coverage helps the agent understand when and how to use this tool effectively.

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