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

Annotations already indicate readOnly, openWorld, idempotent, and non-destructive behavior. The description adds detailed behavioral context: walks the order-book ladder, returns specific fields like top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, and a verdict (clean|degraded|cannot_fill). For basket mode, it explains per-leg fill detail, thin_legs, and forced directional risk. No contradiction 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?

Well-structured: opens with purpose, then required parameters, then separate sections for single-market and basket modes. However, it is quite dense and could be made more concise by omitting some redundant clarifications. The length is justified by the tool's complexity, but there is minor room for trimming.

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?

For a complex tool with two modes and no output schema, the description thoroughly documents return fields: for single-market (top_of_book, vwap_fill_price, slippage_pp, etc.) and for basket (theoretical_sum, realizable_sum, capture_ratio, profit_usd, per-leg fill detail, thin_legs[], max_clean_notional_usd, forced_directional_risk). Also covers edge cases like partial fills and size limits. Complete enough for an agent to understand what to expect.

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 description coverage is 100%, so baseline is 3. The description adds meaning beyond schema: clarifies side defaults for both modes, explains size_usd in basket mode as 'settlement notional — shares per leg, each paying $1 at resolution', and mentions clamp range 10–1,000,000. Adds value but schema already describes parameters adequately.

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?

Specifically states 'Realizable-vs-theoretical edge check against live CLOB order-book depth' and clearly distinguishes two modes (single-market and basket). Explicitly differentiates from sibling tools like polymarket_arbitrage and polymarket_edges by stating when to use this tool before acting on their signals.

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?

Provides 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'. Also explains when not to rely on theoretical overround and warns about partial basket fills converting arb into directional position. Clearly states requirement of providing either market or event.

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