domain_check_to_register

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the no-side-effect profile is covered by structured data. The description adds only that this is an availability check for purchase, and is consistent with the annotations (no contradiction), but says nothing about whether zone_id must come from domain_zones or how the result should be interpreted before registering.

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?

One sentence of purpose followed by a compact Args list; nothing is padded. It is appropriately sized for a three-parameter tool, though the Args block is the only content beyond the first line.

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?

An output schema exists, so return values need no explanation, and the parameters are documented. However, for a check that gates a purchase, the description omits the relationship to domain_add/domain_zones and any note on what a positive vs. negative result implies. Adequate but with clear gaps.

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 0%, so the description carries the full burden — and it does: it explains hostname as the domain name (with an example), zone_id as the domain zone ID, and period as the registration period in years with a default of 1. This meaningfully compensates for the bare schema, though it does not clarify where zone_id values come from.

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?

Names a specific verb+resource: checking whether a domain is available for purchase/registration. That is distinguishable from write-oriented siblings like domain_add and read-oriented domain_list. It does not explicitly name or contrast with any sibling, so it stops short of 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?

The intent (pre-purchase availability check) implies its usage, but the description never states when to call this instead of domain_add, domain_list, or domain_zones, nor that it should precede a registration call. No prerequisites or exclusions are given.

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