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

Annotations already indicate readOnlyHint=true, etc. The description adds critical behavioral details: walks the order book ladder, returns verdict (clean|degraded|cannot_fill), warns about partial basket fills converting arb to directional risk, and explains forced directional risk. This goes well beyond what annotations provide.

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?

Description is well-organized with bold section headers for SINGLE-MARKET and BASKET, uses clear language, and every sentence provides essential information. It is front-loaded with the core purpose. No fluff or redundancy.

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 no output schema, the description comprehensively lists all return fields for both modes (e.g., top_of_book, vwap_fill_price, slippage_pp, thin_legs, max_clean_notional_usd). It explains the edge check concept, covers risks like partial fills and directional exposure, and provides usage thresholds. Highly 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?

Although input schema has 100% description coverage, the description adds significant meaning: clarifies size_usd as 'max spend on buys, target proceeds on sells', explains side auto-detection from partition sum, and distinguishes market vs event in detail. This deepens the agent's understanding beyond 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?

Description clearly states it performs a realizable-vs-theoretical edge check against live order book depth, with explicit modes (single-market and basket) and expected returns. It distinguishes itself from sibling tools like polymarket_arbitrage and polymarket_edges by directing usage before acting on their signals.

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?

Explicitly states when to use: before any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or polymarket_edges trade above ~$500. It specifies required parameters ('REQUIRES one of market or event'), explains default behaviors for side and size_usd, and contrasts single-market vs basket modes.

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