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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false, indicating safe read-only behavior. The description adds important behavioral context: it walks the ladder, returns specific fields like top_of_book, vwap_fill_price, slippage_pp, and warns about partial basket fills converting arbitrage into unhedged directional positions. 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 long but well-structured with clear sections for SINGLE-MARKET and BASKET modes, separated by line breaks. It uses bold headers and bullet-point-style lists for outputs. While every sentence is informative, it could be more concise; however, it avoids unnecessary repetition.

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?

Given no output schema, the description fully enumerates 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 detail, thin_legs[], max_clean_notional_usd, forced_directional_risk for basket. It also covers edge cases like thin books and partial fills, providing comprehensive guidance 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% with good parameter descriptions. The description adds significant meaning: explains how size_usd is interpreted differently between single-market and basket modes (max spend vs. target proceeds vs. settlement notional), clarifies side defaults for basket ('auto from partition sum'), and states the mutual exclusivity of market/event parameters. This is well beyond schema information.

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?

Description clearly states it performs a 'realizable-vs-theoretical edge check against live CLOB order-book depth' and distinguishes two modes (single-market, basket). It names specific outputs and correctly differentiates 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?

Explicitly states when to use: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It also explains why (theoretical overrun not capturable, partial fills cause directional risk), providing clear context and exclusion reasoning.

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