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

Even with annotations (readOnlyHint=true, idempotentHint=true), the description adds rich behavioral context: history is bounded by a 60-day snapshot TTL, snapshots are written on cache-miss so gaps indicate no scan, and decay is computed from daily closes of edge_pp_net, not intraday. It also details the response structure, enabling the agent to understand what data will be returned. No contradictions with 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 long but every sentence contributes. It is structured with clear sections: purpose, args, response (with tracked/expired/snapshot_dates), and limits. The information density is high, and no redundant or filler text exists. Appropriate for the tool's complexity.

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?

For a telemetry tool with no output schema, the description thoroughly covers return values (tracked, expired, snapshot_dates), their semantics, and limitations (TTL, cache-miss gaps, daily vs. intraday). It also explains the implications of gaps and the 'competition clock'. This is exceptionally complete for a tool of this complexity.

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%, so both parameters (days and window) are already well-documented in the input schema. The description essentially repeats the defaults and allowed values (days default 14 max 30, window default '1wk'), adding slight value with the phrase 'snapshot family' but not meaningfully enhancing the schema's semantics. Baseline 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?

Purpose is explicitly stated: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' The description goes beyond a simple verb+resource by explaining the core question ('how long has this edge existed and is it shrinking?') and distinguishes it from sibling tools like polymarket_edges (which likely provides current edges) by contrasting fresh vs. old 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 gives clear guidance on when to use it by explaining the trade context: 'a fresh wide edge and a 3-week-old wide edge are different trades'. It also mentions the 'median lifespan is your competition clock', implying use cases. However, it does not explicitly name alternatives or state when not to use it, so it falls short of a 5.

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