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

Annotations only mark it non-read-only, open-world, non-destructive; the description goes well beyond by stating the campaign cannot deliver or spend until manually activated, that it takes a minute or two, and the exact budget floors and ceiling. This is exactly the behavioral context an agent needs for a mutation that costs money.

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?

Front-loaded with purpose, then the paused/behavioral safety point, then budget limits and prerequisites. Every sentence carries information, though the 'which this tool cannot do and neither can any other' clause is slightly verbose.

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 an 8-parameter mutation with no output schema, the description covers safety, cost constraints, and prerequisites well. It omits what the tool returns (e.g., a campaign ID) and does not explain bid_strategy/bid_amount interaction, so it is strong but not fully complete.

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 coverage is 63% and the description meaningfully enriches two key parameters: budget floors ($6/day for leads and sales, $1/day otherwise; $500/day ceiling) add constraints the schema lacks, and the leads/sales requirement ties to conversion_asset_id and goal. It does not address bid_amount/bid_strategy semantics, leaving a gap.

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?

Specific verb+resource: 'Build a real Meta campaign from chosen concepts, in the client's own ad account, left PAUSED.' It clarifies scope (client's own account, from chosen concepts) and the critical state (paused), letting an agent distinguish it from sibling list/draft tools without opening the schema.

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?

States concrete prerequisites (needs the May plan, a connected Facebook ad account, an X-Mako-Key header) and clarifies the boundary that activation must happen manually in Ads Manager, which no tool can do. It lacks an explicit 'use this instead of X' comparison, but no close sibling alternative exists, so context is clear.

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