Correlate local config with live DNS

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds value by specifying exactly which local files are read and the nature of the cross-check (live DNS correlation), going beyond the annotation safety profile.

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 consists of two concise sentences. The first front-loads the action and resources; the second emphasizes unique value proposition ('No remote service can do this'). No wasted words.

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?

The tool has low complexity (1 optional parameter, no output schema). The description covers inputs and high-level outcome but lacks explanation of return values or output format, which is necessary since no output schema exists.

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 coverage is 100% for the single optional parameter 'domain', so the schema itself provides full meaning. The description does not add any additional context about the parameter beyond what the schema says, meeting the baseline for high schema coverage.

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 verb ('Reads', 'cross-checks', 'surfaces'), the specific resources ('/etc/hosts', 'resolv.conf', 'live DNS'), and the outcome ('explains weird resolution'). It distinguishes from sibling network diagnostic tools by focusing on local config files.

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 local DNS config debugging ('No remote service can do this'), but does not explicitly state when to use this tool versus siblings like dns_lookup or net_diagnose. Guidance on when not to use it is absent.

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