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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds that data limitations are surfaced, which is genuine behavioral context, but says nothing about rate limits, auth, error behavior on unknown ids, or whether missing data is returned as null vs omitted.

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?

A single front-loaded sentence with the verb first and no filler; every clause maps to a distinct piece of returned information. It is efficient, though terse enough that it forgoes routing guidance it could have carried in the same sentence.

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?

An output schema exists so return values need no elaboration, and annotations carry the safety profile, which lowers the bar. Still missing is the one thing an agent needs operationally: where the market id comes from (search_markets) and how to interpret a failure for an unsupported market.

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?

One required parameter with 0% schema description coverage, so the schema does no work here. The description's phrase 'for a market id' is the only signal that the string is an identifier rather than a free-text name, and it gives no format, length, or provenance (e.g., obtained from search_markets), leaving the agent to guess.

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 names a specific verb ('Return') and a precise payload (supported timeframes, available history, data limitations) scoped to a market id. It is clearly distinguishable from search_markets in intent, but it never names or contrasts a sibling explicitly.

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?

Usage is only implied: an agent can infer this is a pre-flight metadata check before a backtest, but the description states no when-to-use condition, no prerequisite, and no alternative. It neither says 'call this before start_backtest' nor warns against using it in place of search_markets.

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