email_domain_check

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

No annotations provided, so description carries full burden. It states what the tool checks (validity, reachability, disposability) but does not disclose whether it makes network calls, has rate limits, or other behavioral traits. The description lacks detail on operational behavior.

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?

Extremely concise: one sentence for purpose and a bullet-like parameter description. No wasted words; every part earns its place.

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 a simple tool with one parameter and an output schema (not shown), the description is nearly complete. It covers purpose and parameter usage. However, it misses guidance on when to use versus similar tools like verify_email, leaving a minor gap.

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?

Only one parameter (email) with schema description coverage 0%. Description adds valuable context by providing the parameter purpose and an example format ('user@example.com'), going beyond the schema's type definition.

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?

Description uses specific verb 'check' and clearly defines the resource 'email domain' with three distinct aspects: validity, reachability, and disposability. This goes beyond the tool's name, avoiding tautology and distinguishing it from sibling tools like verify_email.

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 explicit guidance on when to use this tool versus alternatives. Despite many sibling tools (e.g., verify_email), the description does not mention when to prefer this over others or any exclusions.

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