Price history

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world). The description goes beyond them by disclosing the return payload: low, high, average, % change over the window, and the series. It omits pagination behavior despite a cursor parameter existing, but with no output schema this return-shape disclosure is meaningful added context.

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 with no filler, and the usage cue is front-loaded before the return details. The first sentence's phrasing ('Use for how...') is slightly awkward but costs nothing in ambiguity.

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 four-parameter read tool with no output schema, the description covers purpose and the returned summary fields, which is most of what an agent needs. The remaining gaps are the cursor continuation behavior and the relationship to get_price, neither of which is addressed.

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 item, cursor, points and timestep are already documented in the schema. The description adds only 'over the window' and 'the series', which gesture at the points/timestep semantics without specifying units or pagination, so the baseline 3 for a fully documented schema 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 states a specific verb-like use ('how an item's Grand Exchange price has moved') and the resource (price history), which clearly separates it from a generic lookup. It does not, however, explicitly name or distinguish the very close sibling get_price, so differentiation remains implicit rather than stated.

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 how an item's Grand Exchange price has moved' is a clear when-to-use cue, so usage is implied but not spelled out. No alternative tool is named (get_price is the obvious candidate for current price), and there are no exclusions or prerequisite conditions.

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