Update an item's fields

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

No annotations are provided, so the description carries the full burden. It discloses key behaviors: partial update ('Only the fields you pass are changed') and the cross-list propagation side effect ('updates it everywhere it appears'). However, it omits other important behavioral traits like error handling, permission requirements, or how weightUnit is processed. Adequate but with clear gaps.

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 sentences, front-loaded with the core action, and every word earns its place. The first sentence states the function, the second provides practical use cases and a caveat. No redundancy or 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 tool with 8 parameters, no annotations, and no output schema, the description covers purpose, usage, key behavior, and most parameters. Missing details like weightUnit semantics and error cases are partially covered by schema constraints (e.g., additionalProperties false). Overall, it is sufficiently complete for an agent to select and invoke this tool correctly.

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 compensate. It maps url to 'link', lists most parameters, and explains the critical patch semantics ('Only the fields you pass are changed'). It omits weightUnit, but the enum in the schema makes it self-explanatory. This adds meaningful value beyond the raw 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?

The description opens with 'Patches any subset of an item's own fields', which is a specific verb+resource+scope. It then lists the exact fields (name, description, price, weight, link/url, image URL), clearly distinguishing it from sibling tools like set_item_image_url or set_item_quantity. This makes the purpose unambiguous.

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 description gives concrete use cases ('This is how you rename an item, change its price, or add a link') and notes that only passed fields change. While it doesn't explicitly state when NOT to use it or name alternatives, the context implies when this general patch tool is appropriate versus the more specific field setters.

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