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 discloses that this tool creates new projects (implying a write/mutation operation) and warns against using it for duplication, which adds useful behavioral context. However, it doesn't mention permissions, rate limits, or error handling, leaving some gaps for a creation tool.

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 uses every sentence to provide value without redundancy, such as listing best uses, exclusions, and related tools in a compact format.

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 no annotations and no output schema, the description does a good job covering the tool's purpose, usage guidelines, and behavioral aspects. It addresses complexity by guiding on when to use and what to avoid. However, it lacks details on output or error handling, which could be useful for a creation tool, keeping it from a perfect score.

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 both parameters (name, teamId) documented in the schema. The description doesn't add any parameter-specific information beyond what the schema provides, such as formatting examples or constraints. With high schema coverage, the baseline of 3 is appropriate as the description doesn't compensate with extra 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 clearly states the specific action ('Create a new Railway project') with the resource ('Railway project'), distinguishing it from siblings like project_delete, project_update, and project_list. It goes beyond just restating the name by specifying the domain (Railway) and the creation action.

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' (starting new applications, setting up development environments, creating project spaces) and 'Not for' (duplicating existing projects). It also lists 'Next steps' (service_create_from_repo, service_create_from_image, database_deploy) and 'Related' tools (project_delete, project_update), offering clear alternatives and context for when to use this tool versus others.

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