check_auth

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

With no annotations, the description carries the full burden and does so thoroughly: it discloses the silent 25,000-record cap, the misleading HTTP 200 behavior, the probe's narrow-column download with a few-second runtime, and the key's redaction from URLs.

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 longer than average, but every sentence earns its place: purpose, silent cap warning, run conditions, setup steps, and security considerations are all operationally relevant and front-loaded.

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 diagnostic tool with an output schema, this is complete: it states what is checked, why it matters, when to invoke it, how long it takes, and how to configure the prerequisite. Nothing an agent needs to call it correctly is missing.

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 schema already exhaustively covers inputs. The description adds useful context by clarifying that the key is supplied via NOMIS_UID or NOMIS_CONFIG_FILE, not as a tool parameter.

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 opens with a specific verb and object: 'Report whether the server holds a NOMIS API key, and test the cell limit.' This clearly distinguishes check_auth from sibling data-access tools such as fetch_data and search_datasets.

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?

It explicitly states when to run: 'Run this when a fetch reports truncation, or to confirm setup.' It also explains the consequence of a missing key and how to supply one, giving an agent unambiguous context for invocation.

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