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

Beyond the readOnly/idempotent annotations, the description details mode-specific behavior (walks the ladder, returns top_of_book, vwap_fill_price, slippage_pp, verdict), basket partial-fill risk, and forced_directional_risk. This adds significant context about what the tool computes and warns about unhedged positions.

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 every sentence earns its place—it covers two modes, parameter defaults, output fields, and risk rationale without redundancy. The first sentence states the core purpose, and the rest is dense but organized.

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?

With no output schema, the description lists all key return fields (top_of_book, vwap_fill_price, slippage_pp, shares_filled, max_fillable_usd, verdict; theoretical_sum, realizable_sum, capture_ratio, thin_legs, max_clean_notional_usd, forced_directional_risk) and explains the semantics of clean/degraded/cannot_fill. Combined with annotations and schema, the description fully equips an agent to use this tool.

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?

Despite 100% schema coverage, the description enriches parameter meaning: size_usd is 'max spend on buys, target proceeds on sells' for single-market but 'settlement notional' for baskets; side default is 'auto from partition sum'; market/event select distinct modes. This goes well beyond the schema's basic 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 opens with a specific verb+resource: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It clearly distinguishes this from sibling arb/edge tools by explaining it's a pre-trade fill-risk assessment, not an arb finder or edge scanner.

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?

Explicitly states 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500,' giving clear when-to-use guidance and naming the alternative tools it complements. It also implies exclusions for smaller trades.

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