Add Campaign Creator

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

Annotations already declare it is a non-destructive write with openWorldHint, so the description needn't restate safety. It does add real behavioral value by disclosing deduplication of existing identities, but it leaves open whether a duplicate is a silent no-op or an error, and says nothing about what the idempotency_key guarantees.

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 with zero filler; the primary action is front-loaded. It is efficient rather than bloated, though the brevity is under-specification rather than disciplined economy.

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?

This is a 10-parameter mutation with 0% schema description coverage and no output schema. The description never clarifies which identity fields are required versus optional, what dedup returns to the caller, or how idempotency_key should be generated, so an agent cannot 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% across 10 parameters, so the description must carry the burden and it largely does not. 'Canonical identity or manual username' hints at the creator_id/origin_id versus username split, but nothing explains campaign_id, platform, idempotency_key, email, nickname, country, or notes.

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?

Clear verb+resource: adds a creator to a campaign, and it names two intake modes ('canonical identity or manual username'), which helps distinguish it from update_campaign_creator and copy_campaign_creators. It does not explicitly name or contrast any sibling, so it stops short of a 5.

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?

There is no explicit when-to-use guidance and no mention of the obvious alternatives (update_campaign_creator, prepare_campaign_creator_selection, copy_campaign_creators, create_campaign_creator_import). Usage is only inferable from the tool name and the two intake modes mentioned.

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