nexus_validate_key

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

The annotations already establish readOnly, idempotent, and non-destructive behavior, and the description adds genuinely useful context beyond that: the endpoint is exempt from hourly rate limits and exposes a rate-limit snapshot. This gives the agent actionable knowledge about side effects and operational characteristics not present in the annotations.

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 compact and front-loaded, with the primary purpose stated first. Every sentence adds distinct value: what the tool does, what it returns, and when it is safe/useful to call. There is no filler or repetition of the tool name.

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 zero-parameter, read-only validation endpoint with an output schema and strong annotations, the description is complete. It covers purpose, return values, rate-limit behavior, and recommended usage, leaving no critical information for an agent to call the tool 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 accepts no parameters, and the input schema confirms this. The description does not need to explain any parameter semantics because there are none, so this dimension is not a gap.

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 uses a specific verb ('validate') and a clear resource (the configured Nexus Mods API key), and immediately states the secondary purpose of identifying the account. It also enumerates the returned identity fields, making the tool's function unambiguous and distinct from the many sibling 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 gives explicit usage contexts: checking whether the key works and probing remaining quota via the '_rl' rate-limit snapshot. It also notes the endpoint's exemption from hourly rate limits, making it a safe choice for these checks. It does not name alternatives, but the use cases are clear enough.

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