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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds significant behavioral context beyond these: it explains that the tool walks the order-book ladder, returns specific fields like top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, and a verdict. For basket mode, it details theoretical sum vs realizable sum, capture ratio, profit_usd, per-leg fill detail, thin_legs, and forced directional risk. No contradiction with annotations.

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 a single paragraph but well-structured with capital-letter keywords (REQUIRES, SINGLE-MARKET, BASKET) and front-loaded with the core purpose. While every sentence adds value, it is lengthy and could benefit from tighter wording for easier 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?

Given the tool's complexity (two modes, no output schema), the description comprehensively covers all return fields for both modes, explains edge cases (thin legs, directional risk), and provides sufficient context for correct usage. No gaps identified.

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 baseline is 3. The description adds value by explaining how parameters behave differently across modes: size_usd interpreted as spend/target proceeds for single-market vs settlement notional for basket; side defaults auto for basket based on partition sum. This goes beyond the schema's description but is not extremely detailed per parameter.

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 defines the tool as a realizable-vs-theoretical edge check against live CLOB order-book depth. It specifies two distinct modes (single-market and basket) and explicitly distinguishes its purpose from sibling tools like polymarket_arbitrage and polymarket_edges by stating when it should be used.

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 explicitly states 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It also warns against using it on thin books and explains the risk of partial basket fills converting arb into directional positions, providing clear when-to-use and when-not-to-use guidance.

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