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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the mutation profile is covered. The description adds decision-relevant context beyond that — the operation is free and it produces a grouping object whose id is reused downstream — but says nothing about duplicate handling, permissions or whether edits are reversible.

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, then cost, then the follow-on workflow. Nothing is redundant with the title or schema, and the fragment 'Free.' earns its place as a one-word decision fact.

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 three-parameter mutation with no output schema, the description covers purpose, inputs, cost and the consumer of the result (the campaign id for search_creators). The main gap is failure/duplicate behavior, which an agent would want to know before calling a create tool.

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 100%, so parameters (name defaulting to the brief's first line, brief, status default draft) are already fully documented in the schema. The description adds only framing about what a brief contains and what the returned campaign id is for, which is at the baseline level.

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?

The description gives a specific verb and resource ('Creates a campaign from a brief') and decomposes the overloaded 'brief' parameter into product, goal and creators. It also positions the tool relative to search_creators, though it never contrasts with the sibling list_campaigns or get_campaign_status.

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?

'Free' plus 'Campaigns group the creators you contact; pass the campaign id to search_creators to rank results for the brief' tells the agent exactly when this tool is the right first step in a workflow. No explicit exclusions or when-not guidance are given, which keeps it short of a 5.

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