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

Annotations already mark the tool read-only and open-world, and the description adds meaningful behavior: price can be null in no-trade periods, history reaches up to a year, and results are clamped to the account plan window. No contradiction with annotations.

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 core output is front-loaded in the first sentence, with the key limitation (only hourly, no order book) following immediately. The plan-window sentence is slightly elliptical but 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?

Even without an output schema, the description enumerates the returned fields and the main null/availability behavior, which is enough for a read-only candle endpoint. Pagination and sorting are left to the schema, but no critical calling context 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?

Schema description coverage is 100%, so the schema already explains ticker, limit, cursor, interval, and time bounds. The description mostly restates that candles are hourly and reinforces the 1h interval rather than adding new parameter-level meaning.

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 resource (Kalshi market) and a specific data product (hourly OHLC candles plus volume and open interest), going beyond the tool name. It also distinguishes itself from order-book tools by noting Kalshi serves no historical order book.

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 explicitly frames this as the only historical data source for non-crypto Kalshi markets and says order-book history does not exist, giving clear context for when to choose candles over order-book/snapshot tools. It does not enumerate sibling tools by name or state a when-not-to-use case, but the intended use is clear.

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