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

The description discloses detailed behavioral traits beyond annotations: it walks the order book ladder, returns specific fields like top_of_book, vwap_fill_price, slippage_pp, and verdict. It also highlights the risk of partial basket fills leading to unhedged directional positions, which is critical for understanding tool behavior. Annotations already indicate safe, idempotent, read-only nature, and description adds significant context.

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 relatively long but well-structured: it begins with a concise purpose statement, then uses case formatting (REQUIRES, SINGLE-MARKET, BASKET) to organize content. It is front-loaded with core information and avoids unnecessary fluff. Every sentence adds value given the tool's complexity.

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 lacking an output schema, the description exhaustively lists return fields for both modes (e.g., top_of_book, vwap_fill_price, slippage_pp, verdict for single-market; theoretical_sum, realizable_sum, capture_ratio, profit_usd, per-leg detail, thin_legs, forced_directional_risk for basket). This makes the tool's behavior fully understandable without needing 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?

With 100% schema coverage, the baseline is 3. The description adds practical meaning: it clarifies the requirement for either `market` or `event`, explains default `side` in basket mode, and elaborates on `size_usd` as settlement notional for baskets. This goes beyond schema descriptions, but some parameter details are already 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 clearly states the tool's purpose as a 'Realizable-vs-theoretical edge check against live CLOB order-book depth' and distinguishes between single-market and basket modes. It also explicitly positions itself as a prerequisite before using sibling tools like polymarket_arbitrage, effectively differentiating from them.

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 strong usage guidance, stating 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It also warns about risks like partial basket fills converting arb into unhedged positions. However, it does not explicitly mention when not to use the tool or alternatives, but the guidance is clear and actionable.

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