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 indicates this is a read operation ('List all TCP proxies') and suggests it's for viewing/auditing purposes, but doesn't specify whether it requires authentication, rate limits, pagination behavior, or what format the returned data takes. It provides basic context but lacks detailed behavioral traits.

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 in the first line. The bullet-point format for 'Best for', prerequisites, next steps, and related tools is efficient and organized. Every section adds value without redundancy, making it easy to scan and understand.

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 read-only listing tool with 2 parameters and no output schema, the description provides good context about purpose, usage scenarios, prerequisites, and related tools. However, without annotations or output schema, it doesn't describe the return format or data structure, which leaves some gaps in completeness for an API 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 fully documents both parameters (environmentId and serviceId). The description doesn't add any additional parameter semantics beyond what's in the schema, such as format examples or constraints. 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 clearly states the specific action ('List all TCP proxies') with the target resource ('for a service in a specific environment'), distinguishing it from sibling tools like tcp_proxy_create and tcp_proxy_delete. It explicitly identifies the scope of listing proxies for a service within an environment.

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 on when to use this tool ('Best for: Viewing TCP proxy configurations, Managing external access, Auditing service endpoints'), prerequisites ('Prerequisites: service_list'), next steps ('Next steps: tcp_proxy_create'), and related tools ('Related: domain_list, service_info'). It clearly differentiates this listing tool from creation/deletion alternatives.

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