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

Annotations already declare readOnly and non-destructive, but the description adds valuable behavioral context: snapshots are written only on cache-miss, so gaps indicate no scan; decay is computed on daily closes of edge_pp_net with default slippage, not intraday; and history is bounded by a 60-day TTL. These details inform interpretation of results and are not covered by annotations.

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 well-structured with labeled sections (Args, RESPONSE, LIMITS) and front-loads the primary purpose. Every sentence contributes meaningful information, from the core question to response schema details and data-retention caveats, without filler.

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 compensates by documenting the response structure: tracked[] with full time-series and trend labels, expired[] with lifespan_days, and snapshot_dates[]. It also covers data limitations (TTL, snapshot granularity), making the tool's behavior and output completely understandable.

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 description coverage is 100%, with both 'days' and 'window' already described in detail (defaults, clamps, allowed values). The description restates these ('days (lookback, default 14, max 30), window (snapshot family, default "1wk")') without adding new semantic meaning, so the baseline score of 3 is appropriate.

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 and resource: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' It clearly answers the core question ('how long has this edge existed and is it shrinking?') and distinguishes itself from sibling tools like polymarket_edges by focusing on historical 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 implies when to use this tool by contrasting 'a fresh wide edge and a 3-week-old wide edge are different trades', suggesting it is for assessing edge persistence over time. It provides clear context and even notes data-availability caveats ('gaps mean nobody scanned that day'), but it does not explicitly name alternatives or state 'use polymarket_edges for current edges', so it lacks an explicit exclusion.

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