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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=false), so the description only needs to add context. It adds the append-to-end semantics and the batch bound, but says nothing about retry/idempotency implications (which matter since idempotentHint=false) or what happens on partial failure — a real gap for a batch mutation.

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?

Two brief sentences with zero filler, and the operational constraint (batch size, target list) is front-loaded before the content-quality rule.

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?

No output schema exists, yet the description never indicates what comes back (e.g., created item IDs) or how partial failures are reported. Given a non-idempotent batch write, this leaves an agent without the information needed to handle retries or verification.

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 50%, with nested item fields (title, url, price, priority, etc.) well documented in the schema itself. The description adds the 1–25 batch range and a hint about URL handling, but says nothing about wishlistId validity or how a non-existent wishlist is treated.

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+resource with placement and scale: 'Adds 1–25 items to the end of a wishlist.' The 'to the end' phrasing and batch cap cleanly separate it from siblings like update_item, reorder_items, and create_wishlist without needing to name them.

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?

The guidance given ('Only add what the user asked for; do not invent products or URLs') governs content fidelity, not when to choose this tool over alternatives such as update_item or create_wishlist. Usage context is implied by the append-to-wishlist framing but no exclusions or alternatives are stated.

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