create_service_domain

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

No annotations are provided, so the description must fully disclose behavioral traits. It states the action and resource type but does not mention side effects, required permissions, idempotency, failure conditions, or what happens on duplicate domains. This is a minimal disclosure for a creation 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 a single, focused sentence that conveys the tool's purpose without any redundant or extraneous information. It is front-loaded and appropriately sized.

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?

This is a simple creation tool with low complexity: only 2 parameters, both fully described in the schema, and no output schema. The description states the core action and resource, which is sufficient for an agent to understand its purpose. However, missing annotations and lack of behavioral context slightly reduce completeness.

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 input schema fully describes both parameters (serviceId and environmentId) with 100% coverage, so the description adds no additional parameter semantics. The baseline of 3 applies because the schema carries the full burden.

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 generates a Railway-provided domain (*.up.railway.app) for a service, using the specific verb 'Generate' and a specific resource. It also distinguishes itself from siblings like create_custom_domain and delete_service_domain.

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 implies the tool is for generating the default Railway domain, but it does not explicitly mention when to use it over create_custom_domain or any alternatives. The guidance is only implicit through the mention of 'Railway-provided domain'.

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