Diagnose Userland Nginx Safely

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety bar is lower. The description adds valuable behavioral context: 'without returning configuration or log contents' and 'without a response body' clarify output limitations and privacy safeguards, which goes beyond 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 a single, information-dense sentence covering three distinct actions while staying under 30 words. It is front-loaded with the primary purpose. Slightly complex sentence structure, but every clause earns its place, so it merits a 4.

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 no parameters, strong annotations, and the presence of an output schema, the description is largely complete. It covers the main diagnostic behaviors and explicitly notes what the tool will not return. Some preconditions (e.g., existence of a userland Nginx config) are not stated, but that does not significantly hinder invocation.

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 schema coverage is trivially 100%. The description effectively conveys the optional probing behavior and the non-content-returning nature, making parameter explanation unnecessary. Baseline 4 is appropriate.

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 specific verbs ('Test', 'probe', 'summarize') and identifies exact resources (userland Nginx configuration, loopback port, error severities). It completely avoids tautology and clearly distinguishes itself from sibling tools like whatbox_website_readiness by focusing on syntax testing and error severity summarization.

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 for safe diagnostic checks (read-only, no content return) but does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites. The lack of explicit guidance prevents a higher score.

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