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

Beyond the annotations (readOnlyHint=true, openWorldHint=true, idempotentHint=true), the description adds rich behavioral detail: snapshots written on cache-miss, 60-day TTL, decay computed on daily closes, gaps meaning no scan, and response semantics (tracked vs expired vs snapshot_dates). This far exceeds what annotations alone provide.

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 well-structured with labeled sections (Args, RESPONSE, LIMITS). Every sentence contributes meaningful information about purpose, output, or limitations, so it earns its length despite being dense.

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 structure (tracked, expired, snapshot_dates) and provides interpretation guidance (e.g., median lifespan as a 'competition clock'). It also covers edge cases like snapshot gaps and TTL limitations, making the tool self-contained.

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%, so baseline is 3, but the description adds value by introducing the concept of 'snapshot family' for 'window' and clarifying that 'days' is a lookback with default and max values, which complements the schema's technical 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, descriptive verb phrase: 'Edge persistence and decay telemetry' and states the exact question it answers ('how long has this edge existed and is it shrinking?'). This clearly distinguishes it from siblings like polymarket_edges (which likely lists current edges) and polymarket_arbitrage by focusing on historical persistence and decay.

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 clear context for when to use the tool: to compare fresh vs. old edges and infer that an old wide edge is 'wide for a reason nobody is willing to take.' It does not explicitly name alternatives like 'use polymarket_edges for current snapshots,' but the framing makes the use case clear.

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