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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so safety is clear. The description adds significant behavioral context beyond annotations: it walks the order-book ladder, returns a verdict (clean|degraded|cannot_fill), and explicitly warns about partial basket fills converting an arb into an unhedged directional position—critical risk information.

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 front-loaded with the core purpose. While it is a long single paragraph, every sentence contributes necessary detail for two distinct modes, parameters, return values, and usage guidance. The structure could be improved with paragraph breaks, but no content is wasted.

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 fully compensates by enumerating all return fields for both modes (top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict, theoretical_sum, realizable_sum, capture_ratio, profit_usd, thin_legs, max_clean_notional_usd, forced_directional_risk). It also explains the underlying risk rationale, making it complete for a complex trading 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?

Although the schema already describes all four parameters, the description adds key semantics: it states the mutual exclusivity of market vs. event, clarifies how size_usd is interpreted differently (max spend on buys, target proceeds on sells, settlement notional in basket mode), and explains the side options for each mode. These insights go beyond the schema descriptions.

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 opens with a specific verb+resource: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It clearly distinguishes from sibling tools by explicitly stating 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500,' positioning it as 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?

Provides explicit when-to-use instructions with direct reference to sibling tools and a dollar threshold. It also explains the two modes (single-market vs. basket) and when each is appropriate, including defaults for side and size_usd, giving the agent clear decision criteria.

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