get_execution_cost

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

The description says live mode 'fetches the real top-100 order book per venue independently via ccxt', which is external network access, while the annotations declare openWorldHint=false. That conflicts with the annotation's closed-world claim, so score 1 per the annotation-contradiction rule. The description otherwise adds useful behavioral detail about bundled vs live modes, fallback behavior, and spot-market routing.

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 usage triggers and then details return metrics and mode behavior in a structured way. It is longer than strictly necessary because the Chinese and English usage sentences duplicate the same trigger, though that duplication may be intentional for bilingual routing.

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 an 8-parameter tool with no output schema and only minimal annotations, the description is largely complete: it explains the returned cost components, mode fallbacks, warning behavior, spot-market routing, and the country/exchange interaction. It still does not fully describe every narrative output field implied by the language parameter (advice/warnings/tradeoffs/reasons), leaving a small gap.

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%, so the baseline is 3, and the schema already documents each parameter thoroughly. The description adds valuable cross-parameter semantics, especially that country is required for compliance filtering 'unless exchanges are given explicitly', and it clarifies mode-dependent behavior for spreadMode and spot requests.

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 states a specific verb and resource: it returns per-exchange one-way execution cost in bps and USD for a given order size, including spread, crossing cost, slippage, levels consumed, and fill status. It also names explicit user intents (bid-ask spread, slippage, order-book depth, market impact, execution-cost comparison), which lets an agent distinguish this from sibling tools like compare_exchange_fees or get_funding_rates.

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 has clear trigger conditions: '当用户询问... Use when the user asks about bid-ask spread, slippage...'. It does not, however, name when not to use this tool or explicitly contrast it with the many sibling alternatives (e.g. compare_total_cost, compare_exchange_fees).

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