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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and openness are covered. The description adds that data comes from D1 snapshots at hourly granularity, which hints at stored rather than live data, but it does not disclose retention limits, default behavior, or return characteristics.

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, front-loaded with the data granularity and source, followed immediately by the usage condition. There is no filler.

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 simple two-parameter, read-only tool the description is minimally adequate: it conveys the resource and when to call it. It is incomplete because it omits parameter behavior and, with no output schema, does not describe what the returned time series looks like.

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 only 50%: asset values are listed in the schema, but hours has min/max without a description. The description does not explain how to use asset or hours, nor does it mention defaults or the 720-hour maximum, so it fails to compensate for the schema gap.

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 clear retrieval purpose: hourly history sourced from D1 snapshots, plus the kinds of series available (prices or radar states). It does not distinguish this tool from the sibling query_history, so an agent cannot tell from the description alone which history tool to choose.

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?

It gives a clear usage trigger: 'Call this when you need a time series of prices or radar states.' However, it does not state when not to use it or name alternatives such as query_history, so the routing guidance stops short of being complete.

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