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

Annotations already establish the read-only, non-destructive profile, and the description adds substantial extra context: the data comes from deliberately uploaded scans, a day becomes public only after 3 installs scanned the item on that realm, medians are expressed in copper, and missing data is surfaced explicitly rather than silently omitted. That is meaningful disclosure beyond the annotations, though auth/connection requirements remain only loosely implied.

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?

Five short sentences with no obvious filler, but the ordering scatters provenance, thresholds, units, and caveats without front-loading the core purpose. 'Copper is the median' is a return-value detail that the output schema likely already covers, so it earns less of its place here.

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, the description need not explain return values, and it does cover the key behavioral context an agent lacks: data source, publication threshold, and explicit handling of unavailable data. It stops short of stating connection/auth prerequisites or how to interpret gaps per day, but is largely complete for a two-parameter read 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 coverage is 100%, so both parameters are already documented in the schema and the baseline is 3. The description adds no semantics for realm or itemId (e.g., realm format or id source), so it does not exceed 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 conveys the resource (auction price history per realm/item) but never states a clear verb and reads more like a data-provenance blurb than a purpose statement. It does not distinguish this tool from likely siblings such as market_value or item_page, which an agent would need to choose between.

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?

There is no when-to-use guidance, no conditions that select this tool over market_value or item_page, and no stated prerequisites. The only contextual clue is 'when connected,' which describes behavior rather than when to invoke it.

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