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

Annotations already declare destructiveHint=true and openWorldHint=true; the description adds genuine context by clarifying that further sends stop while leads are retained, which softens the destructive signal for the caller. However it does not explain why the operation is flagged destructive (irreversibility, resumability), nor any permission requirements, so the added value is partial.

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?

Three short, front-loaded lines: action, return, parameter note. No filler, each line carries distinct information, though the parameter note is placed last rather than integrated.

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?

An output schema exists, so the return line is redundant but harmless. With 0% schema coverage across three parameters and a state-changing tool, the unexplained 'validate_only' flag and campaign_id semantics leave the definition short of what an agent needs to call it confidently.

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 compensate: it explains 'workspace' as an optional customer workspace slug (needed only when multiple workspaces exist), which the schema does not. But 'campaign_id' and especially 'validate_only' receive no explanation at all, leaving real gaps.

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 concrete verb and resource ('lemlist-Kampagne pausieren') and distinguishes it from the sibling set (e.g. lemlist_start_campaign, lemlist_update_campaign). The added effect clause clarifies what pausing means operationally, though the German/English mix with the English tool name is slightly awkward.

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 intent of pausing is implied clearly, but the description never states when to pause vs. use lemlist_start_campaign or lemlist_update_campaign, nor any prerequisites (campaign must exist, must be active).

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