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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered without the description. The description adds one useful behavioral fact — 'cost: free' — but says nothing about return volume, ordering, or pagination for a history listing, which is what an agent most needs to know beyond the 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?

A single compact sentence, front-loaded with the category tag and resource, with the cost note trailing. Minor redundancy: the optional filter is stated twice ('可指定策略 ID 过滤' and '参数 strategyId 可选'), which could be collapsed.

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, read-only, single-optional-parameter listing tool whose annotations cover safety and whose schema fully describes the parameter, the description supplies enough to invoke it correctly. Missing only return-shape hints, which are less critical absent an output schema.

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% and the schema already documents strategyId as optional with '缺省返回全部'. The description only restates this ('参数 strategyId 可选'), adding no format, sourcing, or example value beyond what the structured field provides.

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?

States a specific verb+resource (查询回测历史) and scopes it with an optional filter on strategy ID, which distinguishes it from mutation siblings like platform_run_backtest. It stops short of naming the closest read siblings (platform_backtest_result, platform_explain_backtest), so an agent must still infer the boundary from names alone.

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?

'可指定策略 ID 过滤' implies when the filter is useful (single-strategy history vs all), which is real but implicit guidance. There is no explicit statement of when to prefer this over platform_backtest_result or platform_run_backtest, and no prerequisites or exclusions.

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