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

Annotations already mark the tool as read-only and non-destructive, and the description adds substantial behavioral detail: it walks the order-book ladder, returns a verdict (clean|degraded|cannot_fill), and warns that partial basket fills convert an arb into an unhedged directional position. 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 dense and lengthy, but it is front-loaded with the core purpose and uses uppercase mode labels (SINGLE-MARKET, BASKET) to organize behavior. Every sentence carries operational value, though it could be tightened; the high information density slightly sacrifices brevity.

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?

With no output schema, the description enumerates the key return fields for both modes (top_of_book, vwap_fill_price, slippage_pp, verdict; theoretical_sum vs realizable_sum, capture_ratio, thin_legs[], etc.) and names the dominant failure mode (partial fills/unhedged risk). It fully covers prerequisites, modes, parameters, outputs, and risk context.

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%, but the description goes far beyond the schema by explaining mode-dependent meanings: size_usd is 'max spend on buys, target proceeds on sells' in single-market mode and 'settlement notional S (shares per leg)' in basket mode. It also clarifies the market-or-event requirement and side defaults.

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?

Opens with a specific verb+resource: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It clearly distinguishes itself from siblings like polymarket_arbitrage and polymarket_edges by focusing on fill risk versus theoretical edge, and it explicitly names the two modes (single-market and basket).

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?

Provides explicit when-to-use guidance: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500.' It also explains why, citing untracked theoretical overround and partial basket fills creating unhedged directional positions, making the tool's recommended context concrete.

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