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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds significant behavioral context beyond this: the 60-day snapshot TTL bound, that snapshots are only written on cache-miss (so gaps mean no scan), and that decay numbers come from daily closes of edge_pp_net (net of slippage), not intraday. It also explains response structure in detail. No contradiction 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?

Though long, the description is well-structured into explicit sections (Args, RESPONSE, LIMITS). Every sentence carries substantive information: purpose, usage context, parameter meaning, response fields, and limitations. No fluff or repetition of annotations. The density is 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?

The tool is complex (time-series telemetry, trend classification, expired opportunities), yet the description covers all key aspects: how data is derived, what each response field means (including trend enum values), what limitations exist (TTL, cache-miss gaps), and how parameters affect the query. With no output schema and only 2 params, this description is complete enough for an agent to select and invoke correctly.

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 the schema descriptions already cover defaults and ranges. The description adds value by connecting parameters to their conceptual role: 'window (snapshot family)' clarifies that the parameter selects which polymarket_edges snapshot family to read, and the note about lookback depth being bounded by TTL gives purpose to 'days'. This pushes above the baseline 3.

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 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots' and explicitly states the core question it answers: 'how long has this edge existed and is it shrinking?' This clearly specifies the tool's verb (track/measure), resource (polymarket_edges snapshots), and distinguishes it from sibling tools like polymarket_edges by focusing on historical persistence and 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?

The description provides clear context for when to use the tool: it answers the persistence/decay question and explains why the distinction matters ('a fresh wide edge and a 3-week-old wide edge are different trades'). It does not explicitly name sibling alternatives or state 'use this instead of X', but the intent is unambiguous. The lack of explicit exclusions keeps it from a 5.

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