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

Annotations already declare readOnly=false, openWorld=true and non-destructive. The description adds genuinely new behavioral context: 'confirm=false = preview', which tells the agent the call can be safely dry-run, plus the macro-fill behavior where empty message/description delegates to Meta.

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 prerequisites, then formatting details in a compact sequence. Dense but each clause carries information; no filler sentences.

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?

A create tool with an output schema, so return values need no explanation, and the description covers prerequisites, macro syntax, CTA options, and the preview flag. Remaining gaps (status default semantics, fallback_link purpose) are minor.

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 0%, so the description must carry the load. It documents message/description macros, call_to_action enum values, and confirm preview semantics, but leaves name, status, adset_id, account_id, and especially fallback_link unexplained. Partial compensation for an 11-parameter 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 product ad (DPA)') and immediately defines the distinguishing characteristic — one creative that pulls products from the catalog — which separates it from sibling ad creators like create_meta_carousel_ad and create_meta_link_ad.

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?

Gives a concrete prerequisite (the ad set must be catalog-bound, created via create_meta_adset with product_set_id) and routes the agent to list_meta_pages and list_meta_product_sets for required IDs. It stops short of explicitly naming when to prefer this over the other Meta ad-type creators, but the DPA framing implies it.

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