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

Annotations already declare a non-read-only, open-world, non-destructive mutation, and the description adds operationally important behavior by saying the new ad set is always created PAUSED and that dry_run validates. It does not cover authentication, rate limits, or failure modes, so it is useful but not fully rich.

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 definition is front-loaded and dense but not wasteful: one sentence covers purpose, default state, budget condition, targeting, placements, pixel event, and schedule, followed by a short dry-run note. For a 25-parameter tool it stays compact and readable.

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 25-parameter mutation with low schema-description coverage and no output schema, the description gives a good high-level map but omits important operational details such as destination/page prerequisites, bid semantics, excluded audiences, and validation output. It is adequate for selecting and broadly invoking the tool, but not complete for correct use across all options.

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 only 24% across 25 parameters, and the description compensates for some gaps by grouping targeting fields and noting that interest_ids come from meta_targeting_search and that budget applies only when the campaign lacks one. However, it leaves many parameters such as destination_type, page_id requirement, bid_amount, excluded_audience_ids, and language unexplained beyond their names.

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 starts with a specific verb and resource, 'Create an ad set', and scopes it to 'in a campaign', which clearly distinguishes it from sibling campaign and ad creation tools. It also names the core inputs such as optimization goal, budget, targeting, and schedule, so an agent knows exactly what this tool builds.

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?

It gives contextual cues such as budget only if the campaign has none, interest IDs sourced from meta_targeting_search, and dry_run for validation, but it never explicitly states when to choose this over meta_create_campaign or meta_create_ad, nor the prerequisite ordering. Usage is inferable from the resource name rather than explicitly guided.

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