validate_domain_batch

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

With no annotations, the description carries the behavioral burden. It discloses billing per item, the 100-domain cap, cost_usd and call_count_this_month in the response, and the error return shape. It could add more about partial failures or rate limiting, but the key behaviors are covered.

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 compact and well-organized: use case, caveat, argument definition, and return shape. Every line adds information, and the most important constraints are front-loaded.

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?

Given one parameter, no output schema, and no annotations, the description covers invocation and response keys well. The 'data' field inside results is not expanded, but referencing 'same checks as validate_domain' is enough for an agent to know what it contains.

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 explain the domains parameter. It does so effectively by specifying the 1–100 count and the accepted formats (hostnames or URLs), adding meaning the schema's 'array of strings' does not provide.

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 precise operation: validate up to 100 domains in a single call. It explicitly relates to sibling validate_domain and excludes mailbox verification, making the tool's scope and identity clear.

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 clear context: batch validation of up to 100 domains, same checks as validate_domain, and explicitly not mailbox verification. It does not explicitly say 'use validate_domain for a single domain', but the batch framing makes that usage distinction obvious.

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