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. The description adds real value, the cross-exchange flattening, the returned fields, and the cost: free tag, but it says nothing about ordering, pagination, or what an empty result means. With annotations carrying the safety burden and no output schema, this is a modest rather than rich addition.

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 content is a single compact sentence plus a cost tag, front-loaded with the resource and scope before the filtering detail. The 【持仓与执行】 category prefix is mildly redundant with the title but does help group the tool. Nothing meaningful is wasted.

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 two-parameter read-only tool with full schema coverage and no output schema, the description covers what is returned, the cross-exchange flattening behavior, and that it is free. Only result-ordering and empty-state behavior are missing, which is a minor gap at this complexity level.

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 both optional parameters are documented inline with examples (BTC/USDT, binance). The description's '按交易所或交易对过滤' merely restates those two filters, adding no new semantics such as whether filters combine or whether an unknown symbol returns empty versus error. Baseline 3 applies.

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 resource and scope: '我的全部持仓' across exchanges, flattened, with the fields returned (direction/size/entry price/unrealized PnL) spelled out. This makes it distinct from order- or trade-oriented siblings such as platform_trade_history, though it never explicitly contrasts with the similarly named platform_strategy_positions, so sibling differentiation is only implied.

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 states the filtering capability ('可按交易所或交易对过滤'), which is a usable invocation hint, but gives no explicit when-to-use or when-not guidance and no pointer to alternatives like platform_strategy_positions or platform_account_overview. Usage must be inferred from the resource name and field list.

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