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

Annotations already declare readOnlyHint and idempotentHint, but the description enriches behavioral understanding with specifics: it walks the order-book ladder, interprets size_usd differently for buys vs sells, clamps size_usd to 10–1,000,000, and names the output verdict and risk fields (thin_legs, forced_directional_risk). It also explains the danger of partial fills. No contradictions 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, separating single-market from basket modes and listing return fields. It uses all-caps for key warnings and mode distinctions, which aids scanning. However, it is quite long and could benefit from tighter formatting (e.g., bullets), though each sentence carries substantive information.

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, the description is remarkably complete. It explains both modes, return values, risk factors, and the operational context (when to use). Since no output schema exists, the description serves the role of documenting return fields and edge cases. It also clarifies the default side logic and the meaning of size_usd in each mode.

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?

While the schema already covers all parameters (100% coverage), the description adds critical semantics: the default 'auto' behavior for side in basket mode based on partition sum, and the distinction between single-market size_usd (spend/target proceeds) and basket size_usd (settlement notional per leg). It also clarifies market vs event selection. The clamp range is mentioned in the description but not in the schema, adding 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 clearly states the tool's core function: a 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It names specific output metrics (top_of_book, vwap_fill_price, slippage_pp, verdict) and distinguishes between single-market and basket modes. It contrasts with siblings by explicitly referencing polymarket_arbitrage and polymarket_edges, making its unique role clear.

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 gives explicit when-to-use 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 the risk of partial basket fills converting an arb into an unhedged directional position. This goes beyond vague context to actionable alternatives.

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