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

Beyond the readOnlyHint/idempotentHint annotations, the description discloses intricate behaviors: it 'walks the ladder', computes vwap_fill_price and slippage_pp, and returns a verdict (clean|degraded|cannot_fill). It also reveals risk-related behavior such as 'thin_legs[]' and 'forced_directional_risk naming the legs most likely to strand you unhedged', which is critical operational context.

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 meticulously structured with REQUIRES, SINGLE-MARKET, BASKET, and USE THIS sections, front-loading the core purpose. Every sentence carries operational value, with no filler; the density is justified by the tool's two-mode complexity.

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 weight for return-value documentation, and it delivers: it enumerates all return fields for both modes (top_of_book, vwap_fill_price, capture_ratio, profit_usd, thin_legs[], etc.). It also covers edge cases like partial fills and forced directional risk, making it self-sufficient for an agent to decide when and how to invoke it.

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 substantial meaning: it explains that `market` means single-market mode and `event` basket mode, that `size_usd` is 'max spend on buys, target proceeds on sells' in single-market but 'settlement notional S (shares per leg)' in basket mode. It also documents defaults and clamps ('Default 1000, clamp 10–1,000,000'), far exceeding the 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 opens with a specific verb+resource ('Realizable-vs-theoretical edge check against live CLOB order-book depth') that clearly distinguishes it from siblings like polymarket_arbitrage and polymarket_edges. It elaborates two distinct modes (SINGLE-MARKET and BASKET) with explicit output fields, making the tool's function unmistakable.

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?

It explicitly states 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500', naming the exact sibling tools and conditions. It also warns why (theoretical overround not capturable, partial basket fills create unhedged directional risk), providing both when and why guidance.

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