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 effectively discloses that the tool creates a persistent volume (implying a write operation) and provides context on use cases and prerequisites. However, it lacks details on potential side effects, error conditions, or rate limits, which would be helpful for a mutation 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 clear sections (Best for, Not for, Prerequisites, Next steps, Related). Every sentence adds value without redundancy, making it easy to scan and understand quickly. It efficiently conveys essential information 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?

For a mutation tool with no annotations and no output schema, the description does a good job by covering purpose, usage guidelines, and prerequisites. However, it could improve by mentioning what the tool returns or any confirmation details, as there's no output schema. The context is mostly complete but has a minor gap in 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?

The schema description coverage is 100%, so the schema already documents all four parameters. The description does not add any parameter-specific information beyond what the schema provides, such as examples or constraints. Baseline 3 is appropriate as the schema handles parameter documentation adequately.

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 tool creates a new persistent volume for a service, specifying both the action (create) and resource (persistent volume). It distinguishes from sibling tools like volume_list, volume_delete, and volume_update by focusing on creation rather than listing, deletion, or updating.

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, clearly indicating when to use this tool (e.g., for database storage, persistent data) and when not to (e.g., temporary storage, static file hosting). It also lists prerequisites (service_list) and related tools (service_update, database_deploy), 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.