check_nexus_auth

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 the tool's behavior (verification, reporting account status), the output fields, and an environmental dependency (NEXUS_API_KEY). It lacks detail on error handling or exact response format, but for a simple auth check this is adequate.

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?

Three concise sentences with no redundancy. The purpose is front-loaded in the first sentence, followed by return values and usage guidance. Every sentence earns its place.

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 tool with no parameters and no output schema, the description is complete: it states the purpose, lists the expected return values, clarifies the optional environment variable, and gives a direct use case. No additional context is needed for an agent to select and invoke it correctly.

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 tool has zero parameters, so the baseline is 4. The description adds meaningful context by explaining that NEXUS_API_KEY is optional and only relevant to certain tools, which goes beyond the empty schema and helps the agent understand invocation requirements.

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's purpose with specific verbs: 'Verify the Nexus API key works and report account status.' It also specifies the return values (account name, premium/supporter flags, user id), which makes it distinct from sibling tools like crash log and mod lookup tools.

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 explicitly gives a use case: 'Use this to troubleshoot lookup_mod failures.' It also provides context about NEXUS_API_KEY being optional and only needed for Nexus lookup tools, helping the agent decide when this tool is relevant versus alternatives.

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