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

Annotations indicate read-only, idempotent, non-destructive, and open-world. The description adds significant behavioral detail: walks the ladder, returns fields like top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict, and for baskets includes theoretical_sum vs realizable_sum, capture_ratio, profit_usd, thin_legs, forced_directional_risk. No annotation contradiction.

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 dense and front-loaded with the core purpose. It uses capitalization for emphasis and sections for modes. While it could be slightly more concise, every sentence adds value and the structure helps readability. A minor deduction for length, but well-organized.

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 thoroughly explains all return fields for both single-market and basket modes, including edge cases like thin legs and forced directional risk. It also provides practical usage context, making the tool's behavior fully transparent for an AI agent.

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%, yet the description adds meaningful context beyond the schema. For size_usd, it explains 'max spend on buys, target proceeds on sells' for single-market and 'settlement notional' for basket. It also clarifies default side logic for basket mode. This enhances understanding beyond the basic schema descriptions.

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 performs a realizable-vs-theoretical edge check against live order book depth. It explicitly differentiates from sibling tools (polymarket_arbitrage, polymarket_edges) by stating 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'.

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?

Provides explicit when-to-use guidance: before arbitrage signals or edges above $500. Also warns against partial basket fills converting an arb into an unhedged directional position, giving context on when not to rely on the tool alone. Siblings are listed, and the description positions this tool as a prerequisite step.

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