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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered. The description adds real behavioral content beyond that: prospects are copied conditionally, and message campaigns carry settings only, requiring add_message_targets for recipients. It does not say whether the duplicate starts paused/active or what it returns.

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?

Two tight sentences, zero filler, with the core action and the conditional copy behavior front-loaded before the add_message_targets pointer.

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?

No output schema exists, so the description should say what a successful duplicate yields (new campaign ID, initial state), which it does not. For a mutation tool with several sibling campaign tools, that return-value gap is the main missing piece.

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 copyProspects well (default false, prospects excluded unless true), but leaves name and campaignId entirely uninterpreted, so only one of three parameters gets semantic help.

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+resource (duplicate a campaign configuration) with the scoping qualifier 'in the active setup', which separates it from create_campaign and update_campaign in the sibling list. It does not explicitly name those siblings, so it stops short of full differentiation.

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 a clear selection rule: prospects come along only when copyProspects is true, and names add_message_targets as the tool to use when adding recipients to a message campaign instead. It does not address when to duplicate versus build a campaign from scratch with create_campaign, but the context given is solid.

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