⚠️ Apply VAS services

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

Annotations already indicate destructiveHint=true; description adds crucial context: charges money, irreversible, response contains purchase operation IDs for tracking. Also details constraints: each service applied once, stickers only with XL listing, max 3 stickers. No contradiction with annotations.

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?

Description is relatively concise given the amount of information. Uses emoji warnings and numbered hints for important points. However, it is slightly dense and could be broken into clearer sections. Still, every sentence adds value.

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?

Covers purpose, usage, side effects, limitations, and what to do beforehand. Mentions response contains purchase operation IDs. Without output schema, this is sufficient. Could add more detail on response structure, but fine for a complex tool with no output 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%, but description adds value: for dryRun and idempotencyKey, it provides version info and default behavior. For slugs and stickers, it reiterates constraints and points to items_post_vas_prices for available options. For itemId, clarifies it must be a published listing.

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?

Clearly states it applies one or more promotion services and stickers to a published listing. Uses specific verb 'applies' and identifies the resource (VAS services). Distinguishes itself from deprecated siblings (items_put_item_vas, items_put_item_vas_package_v2) by noting it's the current method.

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?

Provides explicit guidance: first check available slugs and prices via items_post_vas_prices, then confirm with user. Also warns about charging money and irreversibility. Mentions that it replaces older methods. Could be more specific about when not to use, but context implies alternatives.

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