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

Annotations already declare readOnly/idempotent/non-destructive behavior, and the description adds valuable behavioral context: snapshots are written only on cache-miss (gaps mean no scan), history is bounded by a 60-day TTL, decay is computed on daily closes not intraday, and edge_pp_net is signed by trade direction. These details go well beyond the structured fields.

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 into intro, Args, RESPONSE fields, and LIMITS. Every sentence earns its place, from explaining response semantics to noting the 60-day TTL. The first sentence front-loads the tool's purpose, and there is no 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?

There is no output schema, yet the description fully documents return shapes (tracked[], expired[], snapshot_dates[]), field meanings, units, and edge cases (cache-miss gaps, TTL, decay limitations). Combined with complete parameter descriptions and informative annotations, an agent can select and invoke this tool with minimal inference.

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%: both parameters have full descriptions with defaults and allowed values ('Lookback in days (default 14, clamp 2-30)' and '24hr | 1wk | 1mo (default 1wk)'). The description repeats similar info (days, window, defaults) without adding significant new meaning, so the baseline 3 applies.

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' and directly answers 'how long has this edge existed and is it shrinking?' It clearly distinguishes itself from sibling tools like polymarket_edges by focusing on historical persistence/decay 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?

It provides clear usage context: use for historical edge persistence and decay, with the warning that a fresh wide edge is a different trade from a 3-week-old one, and 'the median lifespan is your competition clock.' It does not explicitly name alternative tools or state when-not-to-use, but the intended context is unmistakable.

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