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: it returns a verdict (clean|degraded|cannot_fill), details on thin legs, forced directional risk, and how slippage is calculated. It also warns about the 'dominant loss mode in real arb-bot P&L'. 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 well-structured with sections (SINGLE-MARKET, BASKET) and uses bold for emphasis. However, it is quite long (around 200 words). Every sentence adds value, but a slightly more condensed version might be more quickly scannable. No wasted words, but length is borderline.

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 no output schema, the description thoroughly explains return values: top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict for single-market; theoretical_sum, realizable_sum, capture_ratio, profit_usd, per-leg fill detail, thin_legs, max_clean_notional_usd, forced_directional_risk for basket. It also addresses edge cases like partial fills and thin books.

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% (all 4 parameters described). The description goes far beyond the schema by explaining the difference between single-market and basket modes for each parameter (e.g., side interpretation differs, size_usd interpretation differs). It also clarifies defaults and constraints (e.g., size_usd clamp). This adds substantial meaning.

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 function: 'Realizable-vs-theoretical edge check against live CLOB order-book depth'. It distinguishes itself from sibling tools (polymarket_arbitrage, polymarket_edges) by stating it should be used before acting on their signals, and it explains two distinct modes (single-market and basket). This provides a specific verb+resource+scope.

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?

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 (theoretical overround on thin books is not capturable, partial basket fills convert arb to directional position). No when-not-to-use stated, but the positive directive is sufficient.

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