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

Annotations declare readOnlyHint, openWorldHint, idempotentHint as true, and destructiveHint false. Description adds rich behavioral context: walks the ladder, returns top_of_book, vwap_fill_price, slippage, shares_filled, max_fillable, verdict; basket mode returns theoretical vs realizable sums, thin_legs, 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?

Description is dense and informative but somewhat long. It front-loads purpose and required arguments, then details both modes and return fields. Every sentence adds value, but structure could be tightened slightly.

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 is remarkably complete. It explains return fields for both modes, includes practical caveats (thin books, partial fills), and gives usage context. No gaps identified.

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% with descriptions for all 4 parameters. Description adds extra context beyond schema: default values (size_usd default 1000, clamp 10-1,000,000), side defaults (auto for basket), and behavior explanations (e.g., 'max spend on buys, target proceeds on sells').

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?

Purpose is explicitly stated: 'Realizable-vs-theoretical edge check against live CLOB order-book depth.' It distinguishes single-market and basket modes with clear verb+resource (check/fill risk) and differentiates from siblings like polymarket_arbitrage and polymarket_edges.

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 guidance: 'USE THIS before acting on any polymarket_arbitrage SELL/BUY-EVERY-LEG signal or any polymarket_edges trade above ~$500.' It also warns against using when books are thin or fills are partial, explaining the risk of unhedged directional positions.

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