meta_ads_creatives_create_dynamic

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

With no annotations, the description carries the full load and does most of it: it flags the call as mutating, states it is not automatically reversible, names a rollback mechanism (mureo_state_action_log_append) and says it returns the new creative id. It does not describe failure modes, permission errors, or whether the creative is immediately usable in an ad set, so it falls just short of exhaustive.

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?

Five sentences, each doing distinct work: what it is, what it returns, mutation risk, when to use it, and routing to alternatives — with the cardinality constraint last as an operational footnote. No restatement of the name and no filler.

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 13-parameter mutation with nested objects and no output schema, the description covers purpose, return value, reversibility, and asset-count semantics. The omission is the journaling/approval parameters (reason, expected, approval, decision_id) — unusual enough that a sentence on when to supply them would help, though each is well documented in the schema.

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 100%, so the baseline is 3, but the description adds real semantic meaning the schema cannot: the asset arrays are crossed by Meta at serve time rather than zipped, and 2–10 images is 'recommended for meaningful optimization' above the schema's bare minItems of 1. The governance parameters (reason, expected, approval, decision_id) are left to the schema.

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?

States a specific verb and resource ('Creates a Dynamic Creative') and immediately defines the mechanism — Meta auto-generates and optimises combinations from multiple images, headlines, bodies and CTAs — which is exactly what separates it from a static creative call. It also names the two nearest siblings and the condition under which each is preferred.

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?

Explicit selection guidance: 'Use when you want Meta to learn the best-performing asset mix rather than testing manually,' then 'For static single-image ads use meta_ads_creatives_create; for explicitly-controlled multi-card layouts use meta_ads_creatives_create_carousel.' When-to-use and both when-not-to-use alternatives are stated outright.

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