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

Annotations already declare this is a non-destructive write. The description adds genuinely useful behavioral context beyond them: the campaign starts in draft (not launched) and begins with exactly one empty email, which sets expectations about initial state. It omits what the call returns and whether the campaign id is needed for the follow-ups.

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 sentences, front-loaded with the action and then the next steps. No filler, and the sequencing instruction is placed where it is most useful.

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 a simple one-parameter create with no output schema, the description covers purpose, initial state, and follow-up workflow. The one missing piece is what the tool returns (presumably a campaign id) that the named follow-up tools would need.

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% for the single 'name' parameter, so the description could have explained it but does not. The parameter is self-evident and carries a default ('Untitled campaign'), which limits the harm, but by the rule for low coverage the description fails to compensate.

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 ('Create a draft campaign') and the word 'draft' implicitly separates it from launch_campaign and update_campaign among the siblings. It does not explicitly name a sibling, 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 real workflow guidance: 'Use set_sequence to write the emails, then add leads and mailboxes,' which tells the agent the ordering of follow-up tools. It does not state when to avoid this tool or when update_campaign would be preferred, so it is not a 5.

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