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

Annotations declare readOnlyHint and idempotentHint, and the description adds substantial behavioral context: walking the order-book ladder, mode-specific semantics for size_usd, return field details, clamps (10–1,000,000), and the risk of forced directional exposure in basket mode. 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?

The description is dense but well-organized with REQUIRES, SINGLE-MARKET, BASKET, and USE THIS sections. It front-loads a one-sentence summary, then packs mode-specific behavior, return fields, and usage warnings without redundancy. Every sentence earns its place.

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 carries full burden for return values and does so thoroughly, listing all key outputs for both modes (top_of_book, vwap_fill_price, slippage_pp, capture_ratio, thin_legs, max_clean_notional_usd, forced_directional_risk). It covers required params, defaults, modes, and risk factors, making the tool fully actionable.

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 enriches every parameter: side gets default auto logic in basket, size_usd gets mode-dependent meaning (max spend vs target proceeds vs settlement notional/Shares-per-leg), and market/event are explained as mutually required modes. This goes well 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 siblings by naming polymarket_arbitrage and polymarket_edges, and states exactly what it computes.

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?

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 why, citing thin-book overround not capturable and partial basket fills creating unhedged directional positions.

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