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

With no annotations provided, the description carries the full behavioral burden and does it well: it discloses that the campaign is created paused, cannot deliver or spend, takes a minute or two, and has budget floor/ceiling constraints. It does not describe the return format or error behavior, but the essential live-account safety traits are clearly stated.

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?

The description is one tight paragraph with all sentences earning their place. The key purpose is front-loaded, followed by constraints and prerequisites. Minor redundancy exists in 'which this tool cannot do and neither can any other,' but overall it is efficient for an 8-parameter tool.

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 complex creation tool with no annotations and no output schema, the description covers safety and prerequisites but omits important operational details: what the response contains, how bid_strategy relates to bid_amount, and how to choose among parameter combinations. It is adequate but leaves an agent with meaningful gaps.

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?

The description adds meaningful parameter context beyond the schema by explaining budget floors tied to goal type and the $500/day ceiling, which enriches daily_budget and goal. It also indicates run_id comes from a 'May plan.' However, it leaves bid_amount, bid_strategy, campaign_name, and conversion_asset_id semantics mostly to the schema, and the schema coverage is moderate.

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 states a specific verb and resource: 'Build a real Meta campaign from chosen concepts, in the client's own ad account, left PAUSED.' It clearly differentiates this from sibling tools like list_creatives or run_may, and the paused-delivery constraint is prominent.

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 description gives clear context for when the tool is appropriate: it requires a May plan, a connected Facebook ad account, and an X-Mako-Key header. It also states that unpausing cannot be done by this tool or any other, which sets expectations. However, it does not explicitly contrast this tool with alternatives like run_may or list_meta_assets.

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