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

Annotations declare readOnlyHint=true and destructiveHint=false, and the description aligns with this by framing the tool as a simulation/check rather than an execution. It adds substantial behavioral context beyond annotations: walking the ladder, returning verdicts (clean|degraded|cannot_fill), identifying thin legs, and explaining how partial basket fills create unhedged directional risk. Useful operational detail is provided without contradicting structured signals.

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 long but highly structured and front-loaded. The first sentence provides the core purpose, followed by clearly labeled sections for REQUIRES, SINGLE-MARKET, BASKET, and USE THIS. It is dense but every sentence contributes essential information; little waste. For a tool of this complexity (two modes, many parameters, multiple outputs), the length is justified, though a more concise format could have improved readability.

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 is complex, has no output schema, but the description fully compensates: it lists the outputs for both modes (top_of_book, vwap_fill_price, slippage_pp, capture_ratio, profit_usd, thin_legs, etc.), explains the failure mode it prevents, and covers all parameters with contextual meaning. It leaves no significant gaps for an agent deciding whether and how to use the 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% (baseline 3), but the description adds significantly deeper meaning. It explains that size_usd for buys is 'max spend' and for sells is 'target proceeds', and for basket mode it is 'settlement notional — shares per leg'. The distinction between market and event modes is clarified, and side defaults are explained. This goes far beyond the schema descriptions, so a 5 is appropriate.

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 statement. It clearly distinguishes itself from siblings by naming both 'polymarket_arbitrage' and 'polymarket_edges' and describing the two modes (single-market and basket). The scope and function are 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 explicitly states when to use the tool: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It explains the rationale and distinguishes between the two modes, making it clear which parameters to pass in each case.

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