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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, which covers safety. The description adds useful context by noting the tool is optional and that submit_backtest errors provide the real range, and clarifies it lists only assets with real historical data. This goes beyond the annotations without contradicting them.

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 a single, well-structured sentence that leads with the core function and then explains usage context and optionality. Every clause adds value; there is no redundancy or wasted words.

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?

The tool has an output schema, and the description explains purpose, scope, and usage trade-offs with a sibling. It is complete for a read-only list tool. Minor gaps like pagination or result size limits are not mentioned, but these are not essential given the output schema and annotations.

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 100%, with both parameters (backtestApiKey and backtestBaseUrl) already described in the schema. The description does not add parameter-specific semantics beyond what the schema provides, so the baseline score of 3 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 clearly states the tool lists asset pairs with real historical data, including supported timeframes and date ranges. It uses a specific verb ('Lists') and resource ('every asset pair with real historical data'), effectively distinguishing it from the sibling tools submit_backtest and get_backtest_result.

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 description explicitly says the tool is optional and explains the alternative: submit_backtest already returns a clear error with the available range. It gives concrete scenarios for use (up-front exploration, recovering from an 'unknown asset' error) and states it is not required before every submit_backtest.

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