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 write operation ('Create') but doesn't disclose behavioral traits like required permissions, rate limits, or what happens on failure. The description adds some context (e.g., prerequisites, alternatives) but lacks details on mutation effects or error handling, leaving gaps for an agent.

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 symbols (✓, ×, →), making it easy to scan. It's front-loaded with the core purpose and efficiently organized into sections (Best for, Not for, Prerequisites, etc.), with no wasted sentences—each adds value to usage understanding.

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 (creating a service from an image) and lack of annotations/output schema, the description does well by covering usage scenarios, prerequisites, and alternatives. However, it doesn't fully address behavioral aspects like mutation risks or response format, leaving some gaps for an agent to infer, though it's mostly complete for decision-making.

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 parameters (projectId, image, name). The description doesn't add meaning beyond the schema, such as explaining parameter interactions or constraints. With high schema coverage, the baseline score of 3 is appropriate as the description doesn't compensate with extra semantic details.

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 explicitly states the action ('Create a new service') and the resource type ('from a Docker image'), making the purpose clear and specific. It distinguishes this tool from siblings like 'database_deploy' and 'service_create_from_repo' by specifying it's for Docker image-based services, not standard databases or GitHub repos.

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 specific alternatives ('database_deploy', 'service_create_from_repo') and use cases (e.g., custom database deployments, pre-built containers). It also lists prerequisites ('project_list') and next steps, offering comprehensive usage context.

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