Generate Railway Domain

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

No annotations are provided, so the description carries the full burden. It discloses that the tool returns an existing domain URL if one already exists, which is useful behavioral context. However, it doesn't mention potential side effects (e.g., whether this modifies infrastructure, requires permissions, or has rate limits), and the output format is unspecified. For a tool that likely involves infrastructure changes, this is a significant gap.

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 two sentences with zero waste: the first states the core purpose and behavior, and the second adds optional parameter context. It's front-loaded with the main action and efficiently structured, making it easy to parse quickly.

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 complexity (likely involving infrastructure changes), lack of annotations, and no output schema, the description is incomplete. It doesn't explain what a 'domain' entails in this context, potential errors, or the return value format. For a tool with no structured safety or output information, more descriptive detail is needed to guide effective use.

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 both parameters fully. The description adds minimal value by mentioning the optional 'service' parameter, but doesn't provide additional semantics beyond what's in the schema (e.g., format examples or constraints). With high schema coverage, the baseline is 3, and the description doesn't significantly enhance understanding.

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 action ('generate a domain') and resource ('for the currently linked Railway project'), with additional context about returning existing domains. It distinguishes from siblings like 'create-project-and-link' or 'deploy' by focusing specifically on domain generation. However, it doesn't explicitly differentiate from all potential domain-related tools that might exist.

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 usage when a domain is needed for a Railway project, mentioning optional service specification. However, it doesn't provide explicit guidance on when to use this versus alternatives like 'deploy' (which might handle domains differently) or 'link-service', nor does it mention prerequisites like having a linked project. The context is clear but lacks specific when/when-not instructions.

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