haul_verify_email

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

No annotations are provided, so the description carries the behavioral burden. It does disclose a key operational effect ('Costs 1 credit'), which is valuable. However, it does not describe whether a network/deliverability check is performed, side effects, rate limits, or failure 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?

The description is a single compact sentence with no filler. The core purpose is front-loaded and the important cost detail is included cleanly at the end.

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 one-parameter tool, the schema plus description reasonably cover how to invoke it and what it costs. However, with no output schema and no annotations, the description does not explain what the call returns or how edge cases such as invalid emails, timeouts, or credit charges on failure are handled.

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 100% for the single parameter, so the schema already documents what 'email' means. The description reinforces that the email is verified for validity and deliverability but adds no additional parameter-level meaning beyond the schema.

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 uses a specific verb ('Verify') and a clearly scoped resource ('an email address') with concrete outcomes ('valid and deliverable'). It is immediately distinguishable from siblings like haul_verify_phone and haul_check_balance.

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 no guidance on when to use this tool versus alternatives. Sibling names hint at categories, but the description never states a preferred scenario, exclusions, or a condition that would route an agent here instead of another tool.

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