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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds substantial context beyond those: history bounded by 60-day TTL, snapshots written on cache-miss so gaps are meaningful, decay computed on daily closes, edge values are signed by trade direction, and the meaning of expired[] items. This adds depth without contradicting any annotation.

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 relatively long but well-structured with explicit sections (purpose, Args, RESPONSE, LIMITS). It front-loads the core question and then provides precise, non-redundant details. Every sentence adds meaningful information about purpose, parameters, output structure, or limitations. The density is justified by the tool's complexity and lack of an 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?

Without an output schema, the description fully explains the response format (tracked[], expired[], snapshot_dates[]) and the semantics of each field. It also covers edge cases (snapshot gaps, TTL bound, non-intraday decay). Given the tool's analytical nature and two optional parameters, this description is complete enough for an agent to understand what it will receive and how to interpret it.

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% and both params have descriptive schema entries. The description adds extra meaning by explaining 'window' as a snapshot family and reiterating defaults/max values for 'days.' It also ties these params to behavioral context (e.g., decay based on daily closes) rather than just syntax, adding value over the schema alone.

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 phrase: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' It clearly answers a distinct question ('how long has this edge existed and is it shrinking?') and distinguishes itself from the sibling tool polymarket_edges by focusing on time-series persistence rather than current edge values.

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: it explains that a fresh wide edge and a 3-week-old wide edge are different trades, implying this tool should be used when edge age/decay matters. It also states what the tool does NOT provide (no intraday data, bounded by TTL, snapshot gaps). However, it does not explicitly name alternative tools to use instead, though the relationship to polymarket_edges is implied.

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