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

Annotations already declare destructiveHint=true, openWorldHint=true, readOnlyHint=false, but the description adds real behavioral context: it modifies a third-party workspace and 'may make contacts available for outreach there,' plus the human-in-the-loop confirmation requirement. Auth needs and failure modes are still unstated.

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 short front-loaded sentences, with the scope first and the safety prerequisite after. 'This reaches a real person' is echoed verbatim in the confirmed param description, a minor redundancy that keeps it from a 5.

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?

Output schema exists, so return values need no explanation, and annotations carry the safety profile (destructive, open-world, idempotent). The description supplies the missing confirmation and real-person stakes, leaving nothing essential absent for a mutation of this complexity.

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 only 40%, so the description must compensate, and it does partially by pinning 'up to 25 leads' (the maxItems) and 'one provider list or sequence' (destination.type). But provider, destination.id, and activateSequence/skipIfInWorkspace flags are left entirely to the schema, and the confirmation text is essentially duplicated from the confirmed param.

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?

Specific verb+resource+scope: 'Add up to 25 leads to one provider list or sequence' names exactly what the tool does and the bounded size. It is distinguishable from write-siblings like import_external_leads or export_leads_to_crm by the 'external destination' target, but no sibling is named explicitly.

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 clear context and a precondition: it changes a third-party workspace and reaches a real person, so the agent must read wording back and wait for an explicit yes. It stops short of naming alternatives or exclusions (e.g., when to prefer import_external_leads), so it is not a full 5.

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