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

Annotations declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false, so the tool is safe. The description adds: walks the ladder, returns specific fields (top_of_book, vwap_fill_price, slippage_pp, etc.), and warns about forced directional risk and thin legs. 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?

Description is well-structured with clear sections for requirements, single-market, and basket modes. It uses bullet-like formatting for return fields. Every sentence adds value, from purpose to risk warnings. No fluff, front-loaded with core purpose.

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?

No output schema, so description fully details return fields (top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict, and for basket: theoretical_sum, realizable_sum, capture_ratio, profit_usd, thin_legs, etc.). It also covers edge cases like forced directional risk. 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?

Schema coverage is 100%, baseline 3. The description adds meaning beyond schema by explaining size_usd interpretation (max spend vs target proceeds for buys/sells, settlement notional for baskets), side auto-detection in basket mode, and market/event distinction. This adds value, but schema already covers basics.

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 CLOB order-book depth. It distinguishes between single-market and basket modes with specific examples, and the verb 'check' plus resource 'order-book depth' make purpose unambiguous. It differentiates from siblings like polymarket_arbitrage by being a pre-trade risk check.

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 says 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It explains why (theoretical overround not capturable on thin books, partial basket fills convert arb to directional position). This provides clear when and when-not guidance.

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