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

Annotations only declare readOnlyHint=false and openWorldHint=true, so the description carries real weight: it discloses the editToken dependency, the one-of identifier rule, and the non-obvious side effect that token storage may return a new id requiring bookmark updates. It does not cover failure modes or what the response contains.

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 the action, then the precondition, then the body rule, in compact telegraphic prose with no filler. The trailing 'OpenAPI: addWishlistItem' is marginally useful for traceability but is essentially a dangling fragment.

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 9-parameter mutation with no output schema, the description covers the critical prerequisites and side effects but leaves the return shape, error conditions, and several optional parameters (emoji, and how searchKeywords resolves) undocumented.

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 only 22%, so the description must compensate, and it does: it explains that url is a pasted /dp path, that name/title are the display label, and that asin/url/searchKeywords/catalogId are mutually alternative item references. The emoji parameter and the exact one-of exclusivity remain unexplained.

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 ('Add an item to a wishlist') that an agent can distinguish from create_wishlist and create_and_fill without opening a schema. It stops short of explicitly contrasting itself with the sibling create_and_fill, which also populates a wishlist.

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?

'Requires editToken from create' gives the precondition for calling, and the body rule ('name/title plus asin, url (pasted /dp), searchKeywords, or catalogId') tells the agent the item must be identified by exactly one reference source. There is no explicit when-not or named alternative such as create_and_fill.

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