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

The description goes well beyond the annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint) by disclosing: snapshot writing occurs only on cache-miss (gaps mean no scan), history is bounded by 60-day TTL, decay is computed from daily closes net of slippage (not intraday), and edge_pp_net is signed (negative = SELL YES). These are critical behavioral traits that annotations alone do not convey.

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 dense but well-organized with clear sections (Args, RESPONSE, LIMITS). Every sentence adds specific value, from the core question to the explanation of tracked/expired/snapshot_dates and the TTL/slippage limits. No filler or redundancy; the length is justified by the tool's 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?

With no output schema, the description fully explains the response format (tracked[], expired[], snapshot_dates[]) and what each field means, including trend and decay_pp_per_day semantics. It also covers data limitations (60-day TTL, cache-miss gaps, daily-closing basis). This is complete for an agent to understand the tool's behavior, inputs, outputs, and caveats.

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?

The input schema already provides 100% coverage of both parameters (days with default/clamp, window with enum values). The description's parameter mentions ('days (lookback, default 14, max 30)', 'window (snapshot family, default "1wk")') largely repeat schema content. The response breakdown adds context for how days affects snapshot lookback, but this is not a significant addition beyond the schema's 'lookback' description.

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 purpose: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots' and answers a specific question ('how long has this edge existed and is it shrinking?'). This distinguishes it from siblings like polymarket_edges (current edges) and polymarket_arbitrage by focusing on historical tracking and decay analysis.

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 strong context for when to use the tool ('a fresh wide edge and a 3-week-old wide edge are different trades'), making the use case explicit. It does not explicitly name alternatives or state when not to use it, but the context is clear enough to guide selection among sibling tools focused on current edges or arbitrage.

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