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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description earns credit for adding non-annotation context: results are verified available with pricing, and a free API key is required, including where to obtain it.

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?

Three tight sentences with the core capability front-loaded before the return-value and auth notes. The bracketed API-key aside is slightly awkward but genuinely useful, so little is wasted.

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?

There is no output schema, so the description correctly volunteers what comes back (available names with pricing). Combined with annotations covering the safety profile and an explicit auth prerequisite, an agent has nearly everything needed to call it, though a note on latency or result variability would round it out.

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%, so the schema already carries the semantics for tlds, count, industry and description. The description adds no parameter-level detail (e.g., how TLD preferences interact with availability), 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?

States a specific verb+resource ('Generate brandable business names') and adds a differentiating clause about real-time domain availability with pricing, which separates it from siblings like check_domain or brand_conflict_check. It stops short of naming an alternative explicitly, so it falls just below a 5.

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?

No when-to-use or when-not-to-use guidance is given. The description never references the alternatives in the sibling set (check_domain, brand_conflict_check, generate_brand_kit), so an agent must infer routing from the tool name alone.

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