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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is fully covered structurally. The description adds the content shape of the result (price, trends, examine text) but says nothing beyond annotations about rate limits, caching/freshness of the price data, or how open-world lookups behave on unknown items.

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 short sentences, zero filler, with the action and the returned data front-loaded and the argument rule second. Nothing is restated from the title or annotations.

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?

An output schema exists, so return values need not be spelled out, and annotations carry the safety semantics; what remains is adequately covered by the description plus schema. The only gap is the absence of guidance on which sibling to pick for graph/history/compare needs, which slightly limits routing confidence for a tool that sits among several similar price tools.

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 100%, so the baseline is 3, but the description adds a constraint the schema cannot express: mutual exclusivity ('exactly one of' itemId or name), since the schema has no oneOf and zero required parameters. The sibling routing hint (prefer lookup_item for fuzzy search) also lives in the param description and helps disambiguate the two selectors.

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?

Names a specific verb (Get) and resource (current Grand Exchange price for an item) and enumerates the returned data (price, trends, examine text), which is more precise than a tautology. It does not, however, distinguish itself from siblings such as get_item_graph, compare_items, or lookup_item, so an agent can't tell from the description alone when this is the right retrieval tool.

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 one concrete usage constraint — 'Pass exactly one of itemId or name' — which is real invocation guidance. But it offers no when-to-use/when-not guidance relative to the surrounding item/price tools (lookup_item, get_item_graph, compare_items), leaving selection to inference.

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