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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, indicating a safe, read-only check. The description adds valuable behavioral details: it walks the ladder, returns specific metrics (top_of_book, vwap, slippage), and warns about unconverted arb positions. No contradictions.

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 comprehensive but somewhat lengthy. It is well-structured with bold headers ('SINGLE-MARKET', 'BASKET') and a clear usage recommendation paragraph. While every sentence earns its place, the length slightly impacts conciseness. Front-loading of purpose and usage is effective.

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?

There is no output schema, but the description lists all expected return fields (top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict for single; 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, making the tool fully understandable.

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 parameters are well-defined structurally. The description goes beyond the schema by explaining the interplay between `market` and `event` modes, detailing defaults for `side` and `size_usd`, and clarifying how `size_usd` is interpreted differently in single vs basket modes. This adds significant semantic value beyond the bare schema.

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 clearly states it performs a realizable-vs-theoretical edge check against live order-book depth, explicitly distinguishing between single-market and basket modes. It uses specific verbs ('check', 'walks the ladder') and resource names ('CLOB order-book depth', 'polymarket_arbitrage', 'polymarket_edges'), making its purpose distinct from sibling tools.

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 this tool: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It also implies when not to use (small trades) and warns about risks of partial basket fills, providing clear usage boundaries.

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