InstaDomain

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

With no annotations provided, the description carries the full burden. It discloses the return structure (Dict with availability, price in cents, formatted price) and explains the business logic implications (user confirmation required before purchasing). Could be improved by mentioning idempotency or rate limits, but the workflow transparency is excellent.

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?

Well-structured with purpose first, then workflow guidance, then Args/Returns documentation. Every sentence adds value beyond the structured fields. The example value in the Args section is particularly efficient at conveying expected format.

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?

Appropriately complete for a single-parameter tool. While an output schema exists, the description adds necessary context about the relationship between 'price in cents' and 'formatted price' fields. Distinguishes itself adequately from the 8 sibling tools mentioned.

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%, requiring the description to fully compensate. It provides clear semantics ('The full domain name to check') and a concrete example ('coolstartup.com'), giving the agent sufficient context to construct valid inputs despite the schema's lack of descriptions.

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 opens with a specific verb ('Check') and clearly identifies the resource (domain availability and price). It distinguishes itself from siblings like 'buy_domain' by emphasizing this is a pre-purchase check, and from 'check_domains_bulk' by implying single-domain scope.

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?

Explicitly states 'Always call this before buy_domain', establishing clear sequencing. Provides concrete UI guidance ('Show the user the price_display value... and confirm they want to proceed') that explains when to invoke the sibling tool, effectively defining the boundary between checking and buying.

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