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

Annotations (readOnlyHint, openWorldHint, idempotentHint) correctly mark it as non-destructive and safe. The description adds rich detail: walks the ladder, returns fields like top_of_book, vwap_fill_price, slippage_pp, verdict, per-leg fill detail, thin_legs[], forced_directional_risk. It explains the dominant loss mode (partial basket fills). No contradictions.

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?

Well-structured with bold headings (REQUIRES, SINGLE-MARKET, BASKET, USE THIS). Information is front-loaded and logically organized. A bit lengthy but justified by complexity; every sentence adds value. Could be slightly more terse but still effective.

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 covers return values for both modes (top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict for single-market; theoretical_sum, realizable_sum, capture_ratio, profit_usd, per-leg fill, thin_legs[], max_clean_notional_usd, forced_directional_risk for basket). Addresses edge cases, risk, and scaling. Complete for a tool with 4 params and two modes.

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). Description adds beyond schema: explains meanings of 'side' with defaults and auto-mode for baskets, defines 'size_usd' as settlement notional for baskets with clamp range, and clarifies that 'market' and 'event' are mutually required. Adds context not in 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 performs a 'realizable-vs-theoretical edge check against live CLOB order-book depth' and distinguishes between single-market and basket modes with specific inputs and outputs. It uses specific verbs ('check', 'walks the ladder') and resources ('market', 'event'), making the purpose unambiguous.

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 says 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It warns against partial fills converting arb into directional positions, providing clear when-to-use and when-to-avoid guidance relative to sibling tools.

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