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

Annotations already indicate readOnlyHint, openWorldHint, idempotentHint as true, and destructiveHint false, so the description doesn't need to restate safety. It adds behavioral context beyond annotations: walking the order book ladder, returning specific fields like top_of_book, vwap_fill_price, slippage_pp, per-leg fill detail, thin_legs, and forced_directional_risk. It also warns about the dominant loss mode. However, some details (e.g., clamp range) are in the schema, so credit for added context but not over-scored.

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 relatively long but well-structured with clear sections (SINGLE-MARKET, BASKET) and ALL CAPS for emphasis. Every sentence adds value, but some redundancy (e.g., repeating 'default 1000') and verbose phrasing could be trimmed. Still, it remains focused and front-loaded.

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?

There is no output schema, so the description must fully explain return values. It does: for single-market, it lists top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict; for basket, it lists theoretical_sum, realizable_sum, capture_ratio, profit_usd, per-leg fill detail, thin_legs, max_clean_notional_usd, forced_directional_risk. It also covers edge cases (thin legs, partial fills, directional risk). Given the complexity, the description is remarkably complete.

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%, but the description significantly adds meaning: it explains the two modes for parameters (single-market vs basket), the interpretation of size_usd in each mode (spend vs target proceeds vs shares per leg), the default for side (auto in basket mode), and the clamp range 10-1,000,000. This provides crucial context 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?

The description explicitly states the tool's purpose: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It clearly distinguishes two modes (single-market and basket) and is distinct from sibling tools like polymarket_arbitrage and polymarket_edges.

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 provides explicit usage guidance: '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 cause unhedged directional risk) and specifies requirements (market or event).

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