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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds return behavior ('Returns the matching rule entry if found'), but does not disclose what happens when no match is found or what a rule entry contains, so it only partially supplements 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 two concise sentences, front-loaded with the action and result. No wasted words or redundancy with the schema or annotations.

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 is simple with one optional parameter and no output schema, but the description does not specify the structure of the returned rule entry or behavior when no match is found. It is adequate for basic usage but leaves edge cases unaddressed.

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 schema fully documents the 'domain' parameter with a description and default, so the description adds no extra parameter context beyond restating that it searches for a domain. Baseline 3 is appropriate given the 100% 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 tool's function: 'Search the built-in Cealing Host for a domain' — specific verb and resource. It also mentions the return value ('Returns the matching rule entry if found'), which differentiates it from siblings like check_host and generate_host, but the term 'Cealing Host' is ambiguous.

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 searching a domain in the host, but does not explicitly state when to prefer this tool over alternatives (e.g., check_host or forward_proxy). It provides no exclusions or conditions, though the purpose is clear enough for basic usage.

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