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

Annotations already declare it is a non-read-only, non-idempotent, open-world write, so the description's job is to add operational detail — and it does: the 100-domain cap, 1 credit per domain, the free re-enrichment carve-out, and that the call returns a job_id rather than results. It omits whether duplicate domains in one batch are charged twice or how failures are reported.

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?

Two dense sentences with no filler, and the core constraint ('up to 100 businesses you already have') is front-loaded. The credit and return-value facts are packed into a third clause, which is efficient but slightly buries the cost model.

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 an async enrichment job with no output schema, the description supplies the essentials: input scope, cost, and that a job_id comes back. It would be stronger if it said the results are retrieved via the job/results siblings, which is the one thing an agent must know after calling.

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 coverage is 0%, so the description must carry parameter meaning; it conveys the key semantic (the input is domains for businesses you already have) and the domain example in the schema shows the expected format. However, the optional city, state, and business_name fields are never explained, nor is what they are used to disambiguate.

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 and resource ('Enrich businesses ... by website domain') and enumerates the fields it returns (owner name, checked emails, phone line type, tech). The phrase 'businesses you already have' implicitly separates it from discovery tools like start_search/find_locations, though no sibling is named.

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?

Clear context for when to call: you must already hold the domains, up to 100, and a credit is charged per domain with a documented free exception for recently enriched ones. It stops short of stating exclusions or explicitly pointing to alternatives for businesses you don't yet have.

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