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

Annotations already mark the tool as destructive and open-world, but the description adds critical behavioral context: real messages are sent, they cannot be recalled, validation is mandatory in practice, and the final return includes before/after status and verified. This materially improves safe invocation beyond the structured hints.

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 compact and front-loaded: purpose and irreversible effect first, then the validate/confirm/start workflow, then return values, then the workspace parameter. Every sentence adds operational value with no filler.

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?

Given a destructive, open-world action with four parameters and an output schema, the description covers the essential safety workflow, the confirmation requirement, the expected_leads guard, return shape, and workspace handling. Nothing an agent needs to invoke it safely 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?

Schema description coverage is 0%, so the description must carry parameter meaning. It explains validate_only's return behavior, how expected_leads relates to summary.leads_total and what happens without it, and that workspace is the customer workspace slug and optional when only one workspace exists. Only campaign_id is left implicit, which is self-explanatory.

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: start or resume a lemlist campaign. It immediately clarifies the consequential effect that real messages are sent and cannot be undone, which distinguishes this operation from read-only or configuration siblings such as lemlist_pause_campaign or lemlist_update_campaign.

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?

Provides an explicit operating procedure: first call with validate_only=True, show the returned summary or not_ready problems to the user, get confirmation, then start with expected_leads = summary.leads_total. It also states the guardrail that the campaign will not start without matching expected_leads.

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