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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds significant behavioral context beyond annotations: it walks the ladder, returns specific fields (top_of_book, vwap_fill_price, slippage_pp, etc.), and warns about thin legs and forced directional risk. It explains that partial basket fills convert an arb into an unhedged directional position. 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?

The description is fairly long but densely packed with necessary information. It is well-structured with sections for single-market and basket modes, and a usage note. Every sentence adds value, though a slightly more compact presentation could be achieved without losing clarity. Still, it is efficient given the 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?

The tool has 4 parameters, no output schema, and two complex modes. The description comprehensively covers inputs, behavior, and return fields (e.g., top_of_book, vwap_fill_price, slippage_pp, thin_legs). While it doesn't provide a structured output schema, it lists the key output fields and explains their meaning. For the complexity, this is nearly complete.

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 baseline is 3. The description adds substantial meaning: it explains that `market` and `event` select modes, defaults for `side` (auto for basket), and the dual interpretation of `size_usd` (spend vs target proceeds vs settlement notional). It also provides constraints (clamp 10–1,000,000). This goes well 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 description clearly states it performs a realizable-vs-theoretical edge check against live CLOB order-book depth. It explains two distinct modes (single-market and basket) and explicitly distinguishes from sibling tools like polymarket_arbitrage and polymarket_edges by specifying when to use this tool before those actions. The verb+resource combination is specific and unambiguous.

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 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.' It also explains why not using it leads to problems (theoretical overround not capturable, partial fills convert arb to directional position). It contrasts the two modes and their prerequisites (market vs event).

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