UpdateItem

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

Annotations already declare non-readOnly, idempotent, non-destructive, so the safety profile is covered by structured data. The description adds the useful 'at least one change' constraint, but says nothing about what a partial update does to untouched fields or whether archive is reversible (that detail lives in the schema, not the description). 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?

Two sentences, front-loaded with the primary operations followed immediately by the invocation constraint. Nothing extraneous and nothing buried.

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?

With an output schema present and rich annotations, the description need not explain returns. It covers the operation set and the minimum-change requirement, though it omits any note about partial updates or reversibility that would fully round out a multi-field mutation tool.

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 100%, so the schema already documents item_id, status enum, favorite, and progress_percent in detail. The description's listing of change types roughly mirrors the parameters and adds no format or edge-case detail beyond the 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 names specific verbs and the resource: archive/re-queue an item, favorite/unfavorite it, set reading progress. That clearly separates it from tag tools (AddTag/RemoveTag) and DeleteItem/SaveItem siblings. It stops short of naming any sibling or scope boundary explicitly, so it earns a 4 rather than a 5.

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?

'Pass at least one change' gives a concrete invocation constraint, which implies the tool is for one-off state changes rather than bulk or tag operations. However, it never states when to prefer this over SaveItem, DeleteItem, or the tag tools, so usage is only implied.

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