Railway MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states it's a list operation (implied read-only), but doesn't mention pagination, sorting, filtering capabilities, error conditions, authentication requirements, rate limits, or what format the environments are returned in. For a tool with zero annotation coverage, this leaves significant behavioral gaps.

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 a single, efficient sentence that states exactly what the tool does without any wasted words. It's appropriately sized for a simple list operation and gets straight to the point with no unnecessary elaboration.

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 simple list tool with one well-documented parameter but no annotations or output schema, the description is minimally adequate. It tells what the tool does but lacks behavioral context about how it works, what it returns, or when to use it. The combination of purpose clarity and parameter documentation meets basic requirements but leaves gaps in usage and behavior.

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 the single parameter 'projectId' fully documented in the schema. The description doesn't add any parameter information beyond what the schema provides (it doesn't explain what constitutes a valid project ID or where to find it). With complete schema coverage, the baseline score of 3 is appropriate.

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 'List all environments in a project' clearly states the action (list) and resource (environments in a project). It distinguishes from siblings like project_list (lists projects) and deployment_list (lists deployments), but doesn't explicitly differentiate from domain_list or volume_list which list different resources. The purpose is specific but could be more distinctive.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, timing considerations, or compare with sibling tools like deployment_list or service_list that might list related resources. The agent must infer usage from the tool name and context alone.

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