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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description adds substantial behavioral context: it walks the order book ladder, returns specific metrics like vwap_fill_price and slippage_pp, and warns that partial basket fills convert an arb into unhedged directional risk. This goes well beyond the annotations and explains real-world behavior and failure modes.

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 but well-organized: it leads with the core purpose, then uses REQUIRES to separate modes, and each mode's behavior and outputs are listed clearly. While long, every sentence carries essential information for a complex two-mode tool. The use of capitalization and explicit labels helps navigation.

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?

The tool has no output schema, yet the description fully enumerates the return fields for both modes (top_of_book, vwap_fill_price, etc. for single-market; theoretical_sum, capture_ratio, thin_legs, etc. for basket). It also covers edge cases like forced_directional_risk and max_clean_notional_usd, making the tool's behavior predictable without needing additional documentation.

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%, so the baseline is 3. However, the description enriches parameter meaning significantly: size_usd is defined as 'max spend on buys, target proceeds on sells' for single-market and as 'settlement notional S' for basket mode, and side behavior is clarified for both modes. This adds interpretive value 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 'Realizable-vs-theoretical edge check against live CLOB order-book depth,' which is a specific verb+resource pairing that clearly states what the tool does. It distinguishes itself from siblings by explicitly naming polymarket_arbitrage and polymarket_edges as tools to precede, making its unique role 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?

The description 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 the two modes (single-market vs basket) and the required parameters for each, giving clear context and exclusions (e.g., no need for small trades).

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