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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds substantial context: 60-day snapshot TTL, gaps caused by cache-miss days, decay computed from daily closes of edge_pp_net, and the signed meaning of edge_pp_net (negative = SELL YES). It also explains the historical depth limitation. This goes well beyond the annotation hints.

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 intentionally structured into purpose, args, RESPONSE, and LIMITS sections. Each sentence carries information, though some phrasing (e.g., 'the latter is wide for a reason nobody is willing to take') is illustrative but not essential. It is well front-loaded with the core question it answers.

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 return structure: tracked[], expired[], and snapshot_dates[], including fields like trend, decay_pp_per_day, lifespan_days, and edge_pp_net. It also covers data gaps, TTL, and computational basis. For a telemetry tool, this is complete and actionable for an agent.

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% for both parameters, so the description need not restate them. The description adds useful semantic context: window is described as a 'snapshot family' and days as a lookback with default/max values. It also connects the response fields to the parameter behavior (e.g., 'snapshot_dates[] = which days actually have data'). This adds 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 clearly states it provides 'edge persistence and decay telemetry' and answers a specific question: 'how long has this edge existed and is it shrinking?' It uses a specific verb+resource and distinguishes itself from sibling polymarket_edges by focusing on historical persistence rather than current 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?

The description implies when to use it: for understanding edge longevity and decay, contrasting 'a fresh wide edge and a 3-week-old wide edge.' It does not explicitly name alternatives or exclusion criteria, but the context is clear enough for an agent to select this tool for temporal edge analysis.

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