refinery_get_price_history

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

The description adds a critical behavioral trait not present in annotations: this is a paid lookup costing $0.25 via x402, with an environment-variable escape hatch. This goes well beyond the readOnlyHint and destructiveHint annotations and tells the agent what operational consequence to expect.

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?

The description is two sentences with no filler: the main purpose is front-loaded, and the second sentence delivers the important payment condition. Every sentence earns its place.

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 read-only single-resource lookup with an available output schema, the description, combined with annotations, is complete enough. An agent knows what the tool does, what input it needs, that it is safe, and that it has a cost implication. No critical call-blocking detail is missing.

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?

The description names the central required input, 'ZPID', which is helpful, but it does not explain the params wrapper or the optional response_format, and it adds little meaning beyond what the input schema already provides for zpid and response_format. The schema coverage signal is low, so the description only partially compensates.

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 action ('Get'), a specific resource ('price-history timeline'), and the key input ('by ZPID'). This clearly distinguishes it from sibling tools like refinery_get_tax_history and refinery_get_schools, which cover different property subresources.

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 usage context is implied rather than explicit: an agent can infer this tool is for price-history lookups, but the description does not explicitly name alternatives or state when not to use it. The paid-lookup caveat is a cost consideration, not guidance about choosing between sibling tools.

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