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 does well by indicating this is a configuration update tool (implying mutation), listing related tools that suggest behavioral relationships, and mentioning prerequisites that imply dependencies. However, it doesn't explicitly state permission requirements, rate limits, or whether changes are reversible/destructive.

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 clear sections (Best for, Not for, Prerequisites, Next steps, Related) and uses efficient bullet points and symbols. Every sentence earns its place by providing actionable guidance without redundancy. The information is front-loaded with the core purpose statement.

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 10 parameters and no annotations/output schema, the description does an excellent job providing usage context, alternatives, and workflow relationships. The main gap is the lack of explicit behavioral warnings about permissions, destructiveness, or rate limits that would be important for a configuration update 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?

Schema description coverage is 100%, so the schema already documents all parameters thoroughly. The description doesn't add any parameter-specific information beyond what's in the schema. However, it does provide context about environmentId being 'usually obtained from service_info' which adds practical usage insight.

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 explicitly states 'Update a service's configuration' which is a specific verb+resource combination. It clearly distinguishes this tool from siblings like service_restart, variable_set, and deployment_trigger by listing what it's not for, making its purpose unambiguous.

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 excellent usage guidance with explicit 'Best for' and 'Not for' sections, naming specific alternative tools for excluded use cases. It also lists prerequisites (service_list, service_info) and next steps (deployment_trigger), giving comprehensive context for when and how 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.