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

Annotations declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds rich behavioral context: it walks the order-book ladder, returns verdicts (clean|degraded|cannot_fill), identifies thin_legs and forced_directional_risk, and flags the strategic danger of partial basket fills. This goes far beyond the annotation hints and proactively discloses important failure modes.

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 exceptionally dense and well-organized. It front-loads the core purpose, then uses clear uppercase labels (SINGLE-MARKET, BASKET) to structure detailed behavior, parameters, and outputs. Every sentence adds substantive information; there is no filler or tautology. The structure aids quick comprehension despite 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?

Given the tool's complexity and the absence of an output schema, the description fully enumerates return values for both modes (top_of_book, vwap_fill_price, capture_ratio, profit_usd, per-leg fill detail, thin_legs, max_clean_notional_usd, etc.), explains parameter semantics in context, and provides a clear usage rationale. It is sufficiently complete for an agent to select and invoke the tool correctly.

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 the schema already documents each parameter well. The description adds the critical business rule that exactly one of `market` or `event` is required, and clarifies the mode-dependent interpretation of `size_usd` and `side` defaults (e.g., auto detection based on partition sum). While some of this is repeated from the schema, the exclusive-or constraint and the mode-specific usage guidance provide meaningful added value.

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 and resource: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It clearly distinguishes two modes (single-market and basket) and enumerates outputs. It explicitly references sibling tools (polymarket_arbitrage, polymarket_edges) and positions itself as a pre-trade risk check, making its purpose 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?

The description states exactly 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 provides a clear decision threshold, explains why (theoretical overround is not capturable on thin books, partial fills create unhedged directional risk), and implies when it is necessary without ambiguity.

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