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

Adds substantial context beyond the annotations: a 30-second vendor timeout, credit consumption, the confirm gate, and the caveat that unknown/catch-all results do not guarantee delivery. These are exactly the cost, latency and result-trust facts an agent needs before calling a non-idempotent, credit-spending tool.

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?

Four compact sentences, each carrying distinct information (timeout, cost gate, result caveat, retry rule), with the core action front-loaded. Slightly telegraphic but no wasted text.

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 two-parameter tool with no output schema, it covers cost, latency, prerequisites and result interpretation caveats. It does not say what the response contains (e.g. status values returned), which would help since there is no output schema to fall back on.

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%, so the description must carry parameter meaning — and it explains the non-obvious 'confirm' flag, which the schema documents only as a boolean defaulting to false. It says nothing extra about the email parameter, but the schema's format/pattern/maxLength already constrain that fully.

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 ('Verify one address') and the 'one' explicitly scopes it against the bulk siblings. An agent can distinguish it from bouncify_start_bulk_verification or bouncify_create_bulk_list without opening either schema.

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?

Gives concrete preconditions ('requires confirm:true') and a prohibitive rule ('Never automatically retry an uncertain response'), which directly shapes invocation behavior. It implies but never names the bulk alternative as the multi-address path, so routing guidance is slightly incomplete.

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