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 effectively communicates that this is a creation/mutation tool (implied by 'Create'), specifies use cases and exclusions, and mentions prerequisites and next steps. However, it lacks details on permissions, rate limits, or error handling, which would be valuable 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 and front-loaded with the core purpose, followed by organized sections (Best for, Not for, Prerequisites, Next steps, Related). Every sentence adds value without redundancy, making it efficient and easy to parse.

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 as a mutation operation with no annotations and no output schema, the description does a good job covering purpose, usage guidelines, and workflow context. However, it could improve by including more behavioral details like response format or error scenarios, which are important for a creation tool.

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 thoroughly. The description does not add any parameter-specific information beyond what the schema provides, such as format examples or constraints. This meets the baseline expectation when schema coverage is high.

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's purpose with a specific verb ('Create') and resource ('new persistent volume for a service'), distinguishing it from siblings like volume_list, volume_delete, and volume_update. It explicitly defines the scope as persistent storage creation.

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, listing specific use cases (database storage, persistent data, file storage) and exclusions (temporary storage, static hosting, caching). It also mentions prerequisites (service_list) and next steps (volume_list), offering clear context for when to use this tool.

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