Item facts

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds that all versions are returned and that GE price is included only when tradeable, which is useful. It says nothing about the cursor/pagination behavior for long lists, so it adds only moderate value beyond 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?

One dense, front-loaded sentence with no filler; each enumerated clause describes actual returned data. It is slightly list-heavy but nothing is wasted.

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 no output schema, the description carries the return-value burden well by naming the fields returned. The main gap is silent pagination behavior despite a cursor parameter being present, which matters for an item with many versions.

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 both parameters ('item' name or id, and 'cursor') are already documented in the schema. The description mirrors 'by name or id' but adds no new meaning, and the cursor continuation parameter is unaddressed. Baseline 3 is appropriate.

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 gives a specific verb+resource (facts about an item) and enumerates the returned fields, including live GE price when tradeable. It is clear what the tool does, but it never names sibling tools like get_price or find_item_sources, so the agent must infer the boundary itself.

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?

'Use for facts about an item by name or id' implies the use case, and the mention of GE price hints at overlap with get_price. However, there is no explicit when-to-use vs alternatives guidance and no exclusions, leaving routing to inference.

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