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

Beyond the readOnlyHint=true annotation, the description discloses significant behavioral nuance: snapshots are only written on cache-miss, gaps mean no scan occurred, history is bounded by a 60-day TTL, and decay is computed from daily closes net of slippage, not intraday data. It also explains the difference between tracked and expired entries, giving the agent a clear model of what to expect.

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?

Although the description is verbose, it is highly structured with labeled sections (purpose, Args, RESPONSE, LIMITS) and every sentence delivers critical operational detail. The front-loaded purpose sentence immediately establishes what the tool does, and the response field breakdown replaces the missing output schema.

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 documents the response fields (tracked, expired, snapshot_dates), their semantics, and edge cases such as TTL gaps and signed edge values. It also provides competitive context ('the median lifespan is your competition clock') that helps the agent decide when this tool matters.

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 clear descriptions for both parameters, so the baseline is 3. The description's 'Args' line mostly restates the schema ('lookback, default 14, max 30' vs schema 'clamp 2-30') and does not add substantial new meaning. The conceptual detail about snapshot families appears in both schema and description, so no extra value beyond the schema.

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 pairing: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' It clearly distinguishes this from sibling tools like polymarket_edges (current edge listing) and polymarket_arbitrage by focusing on the time dimension: 'how long has this edge existed and is it shrinking?'

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 states the tool's purpose in answering a specific question and explains how to interpret results (e.g., 'a fresh wide edge and a 3-week-old wide edge are different trades'). It does not explicitly name alternative tools or state when not to use it, but the contrast with current-edge tools is strongly implied through the persistence/decay framing.

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