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

Annotations already declare destructive/openWorld/non-idempotent, but the description adds behavior annotations cannot express: the exact cost model (2 tokens per person, up-front reservation of 2 tokens per lead id, settle on delivery), the async job-id + get_job_status polling contract, and a full outcome vocabulary (verified/published/catch_all/searched) with what each means.

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?

Front-loaded with the triggering condition, then cost, then sibling differentiation, then return/polling behavior. Dense and mostly waste-free, though the cost/reservation sentences are slightly circuitous and could be tightened without losing meaning.

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 expensive, mutation-like, open-world tool with no output schema, the description supplies everything needed: eligibility, cost ceiling, async polling path, and the meaning of each possible per-lead outcome. Nothing an agent needs to call it correctly is missing.

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?

There is only one parameter and schema coverage is 100%, so the schema already documents result_ids including the eligibility and skip-without-charge rule. The description's added value here is limited to tying cost to 'per lead id sent', which is marginal on top of the schema. Baseline 3 for a fully-covered single parameter.

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 chain: search the open web for named people (owner/founder/director), then resolve and verify their email in one run. It explicitly contrasts itself with 'enrichment', so an agent can route correctly without inspecting 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?

Prequalifies the audience precisely: 'for leads with a website but no named contact', and names the alternative (enrichment) along with the condition that selects it (people listed on the business's own site, already free). It also flags the case this uniquely reaches that enrichment cannot.

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