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 profile is covered. The description adds minimal behavioral context beyond that, such as the output concept of suggestions, but does not disclose ordering, pagination, or vocabulary behavior.

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 clear, front-loaded sentence with no fluff beyond the redundant 'addPrefixToDomain:' heading that repeats the tool name. It is appropriately short and readable.

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 simple read-only suggestion tool, the description conveys the core output (domain suggestions) and all parameters are fully documented. The absence of an output schema is mitigated by the intuitive result type, though no details about response structure are given.

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 description coverage is 100%, with all five parameters already documented in the input schema. The description contributes no additional parameter semantics, so the baseline 3 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 a specific verb ('Generate') with a specific resource ('domain suggestions') and a precise method ('adding prefixes to a base name'). This clearly differentiates it from the sibling addSuffixToDomain and other suggestion tools by identifying its distinct mechanism.

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 no guidance on when to use this tool versus close alternatives like addSuffixToDomain, generateDomainSuggestions, or bulkDomainSuggestions. There are no explicit conditions, exclusions, or pointers to a more appropriate sibling.

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