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

Annotations declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false. The description goes well beyond this by explaining that the tool walks the order-book ladder, returns specific metrics like top_of_book and vwap_fill_price, and details the risk of partial basket fills converting an arb into an unhedged directional position. This is rich behavioral context not available from annotations alone.

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 (250+ words) but each sentence carries useful information. It is well-structured with 'SINGLE-MARKET:' and 'BASKET:' sections, and the opening sentence front-loads the core purpose. However, it could be slightly more concise by using bullet points or splitting into shorter paragraphs; the density of information makes it a bit heavy to parse.

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, yet the description enumerates all major return values for both modes (top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict; theoretical_sum, realizable_sum, capture_ratio, profit_usd, per-leg fill detail, thin_legs[], max_clean_notional_usd, forced_directional_risk). It also covers input preconditions, mode selection, and use-case context, making it fully self-contained.

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?

Though schema coverage is 100%, the description adds significant meaning: it clarifies that `market` and `event` select mutually exclusive modes, explains `side` defaults for each mode (including auto-detection in basket mode), and gives different interpretations of `size_usd` (max spend on buys vs target proceeds on sells vs settlement notional in basket mode). This goes 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 opening sentence 'Realizable-vs-theoretical edge check against live CLOB order-book depth' clearly states a specific verb ('check') and resource ('live CLOB order-book depth'). It distinguishes itself from sibling tools by focusing on fill risk rather than opportunity discovery, and explicitly references polymarket_arbitrage and polymarket_edges as related but different 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 the tool: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500'. It also explains the rationale (theoretical overround on thin books is not capturable) and describes two distinct modes (single-market vs basket) with clear guidance on when each applies.

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