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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, and the description aligns with those. It adds extensive behavioral context: walks the order-book ladder, returns per-leg fill detail, identifies thin_legs, forced_directional_risk, and warns about partial-fill conversion to unhedged positions. This exceeds what annotations convey.

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 and dense, but it is front-loaded with core purpose and then separates single-market vs basket modes clearly. Every clause adds operational detail needed for correct invocation. It could be tightened, but complexity justifies the length.

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 must explain return values, and it does comprehensively: verdict values, fields like top_of_book, vwap_fill_price, slippage_pp, shares_filled, theoretical_sum vs realizable_sum, capture_ratio, etc. It also covers prerequisites (market or event) and risk context. Nothing critical is missing.

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 adds rich semantics beyond the schema: size_usd interpretation changes by mode (max spend vs target proceeds vs settlement notional), side defaults, and default behavior in basket mode (auto from partition sum). This is far beyond baseline schema documentation.

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 begins with a specific verb+object: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It clearly distinguishes itself from siblings like polymarket_arbitrage (signal generation) and polymarket_edges (theoretical edges) by focusing on fill risk against live book depth.

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 usage guidance: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500.' It also explains when basket mode is appropriate and warns about partial fill risks, making the when-to-use unambiguous.

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