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

Annotations already state readOnlyHint=true, idempotentHint=true, and destructiveHint=false, but the description adds substantial behavioral detail: it 'walks the ladder', returns specific metrics, and discloses risk implications like 'thin_legs' and 'forced_directional_risk' that could strand the user. This goes far beyond the annotations without contradicting them.

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 long but front-loaded with a crisp one-sentence summary. It is structured with clear mode labels (SINGLE-MARKET, BASKET) and lists output fields. A few unnecessary capitalizations and dense phrasing detract slightly, but every sentence adds value and the structure aids scanning.

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?

Despite having no output schema, the description enumerates all return fields for both modes (e.g., top_of_book, vwap_fill_price, slippage_pp, capture_ratio, profit_usd, thin_legs). It also covers edge cases like defaults, clamps, and the risk of partial fills, making it fully contextually complete for a complex 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 input schema has 100% coverage, but the description enriches the parameters further: it explains that size_usd is 'max spend on buys, target proceeds on sells' in single-market mode and 'settlement notional' in basket mode, with default and clamp values. It also clarifies that `market` and `event` are mutually exclusive modes, which is not explicit in the schema.

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 'Realizable-vs-theoretical edge check against live CLOB order-book depth' which clearly states the verb (check) and resource (fill risk against order book depth). It distinguishes itself from sibling tools by explicitly naming when to use it ('USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'), setting it apart from arbitrage and edge detection tools.

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 provides explicit usage context: the two modes (single-market and basket) and when to invoke each, plus a clear directive for when this tool should be used vs alternatives. It even explains the failure mode it prevents ('partial basket fills convert an arb into an unhedged directional position'), which is strong when-to-use guidance.

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