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 two useful behavioral facts beyond that: it returns empty when no credentials are configured, and it costs nothing ('cost: free'). It still gives no signal about return shape or freshness of the balance/position data, which matters for a snapshot tool with no output schema.

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?

One dense line with the scope front-loaded and the most call-decisive constraint (empty without credentials) placed before the trailing cost tag. The bracketed category prefix 【持仓与执行】 is organizational metadata rather than tool-specific value, but it costs little.

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?

With zero parameters, no output schema, and annotations covering the read-only/non-destructive profile, the description supplies everything an agent needs: what is aggregated, whose account, the empty-result precondition, and cost. No call-decisive fact is missing for a parameterless read tool.

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?

The tool takes zero parameters, so there is no parameter semantics to explain; baseline for a no-param tool applies. Nothing in the description misdescribes inputs, and the absence of arguments is consistent with a 'my account' scoped read.

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 pairs a specific resource with a scope qualifier: a cross-exchange ('跨所') account overview covering per-exchange balances, positions, and currency aggregation. That distinguishes it from narrower siblings such as platform_positions or platform_credentials, though it never names those siblings explicitly, so the differentiation must be inferred.

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 implied rather than stated: 'my account overview' points to checking aggregated account state, and the parenthetical 'returns empty without credentials' signals a prerequisite. However, it never says when to prefer this over platform_positions or when to go to platform_credentials first, leaving alternative selection to inference.

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