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

Annotations already establish that this is read-only, non-destructive, and closed-world. The description adds substantive behavior beyond that: merging trades by date, reporting same-day co-trading and co-loss frequency, worst-day comparison, win/loss correlation, and scaling each strategy from its own starting balance. It does not cover error handling or computational limits, but it adds meaningful context.

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 front-loaded with the intended user scenario and then lists the reported analyses. It is dense but largely free of filler, though the long middle sentence could be easier to scan.

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 moderately complex analysis tool with no output schema, the description supplies the key prerequisites, inputs, and reported comparisons. It does not describe the exact return structure, but it gives enough context for an agent to decide when and how to call it.

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%, so the description needs to compensate. It explains starting-balance scaling and challenge_ids account selection, but its statement that every trade needs a close date conflicts with the schema, which allows dates for every trade or none. It also omits other schema details like trade ordering and optional strategy names.

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 opens with a clear scenario and states that it merges trades by date and reports overlap metrics. It is specific about the resource and operation, but it does not explicitly differentiate itself from siblings such as compare_challenges or test_stats, stopping short of a 5.

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 clear usage context: for a trader running two to five strategies on one account, with optional account selection via challenge_ids. It does not state when not to use the tool or name alternatives, so it is not a 5.

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