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

Annotations declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral context beyond annotations: snapshots are written only on cache-miss causing gaps, history depth is bounded by a 60-day TTL, and decay numbers are computed from daily closes, not intraday. This fully discloses operational nuances and limitations.

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 efficiently structured with ARGS, RESPONSE, and LIMITS sections. Every sentence adds critical information about inputs, output shape, and constraints. No filler or redundant phrasing; the density is justified by 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?

Despite having no output schema, the description explicitly defines the response structure (tracked[], expired[], snapshot_dates[]) and key fields (edge_pp_net, trend, decay_pp_per_day, lifespan_days). It also explains limitations (TTL, snapshot gaps, daily closes). Given the tool's complexity and absence of an output schema, this description is remarkably complete.

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 parameters (days, window) have descriptive schema text. The description essentially repeats these (default 14, max 30 for days; default '1wk' for window) without adding new semantic meaning beyond what the schema already provides. The baseline of 3 applies, as the schema does the heavy lifting.

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 clearly states a specific verb+resource: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' It answers a concrete question ('how long has this edge existed and is it shrinking?') and differentiates from the sibling tool polymarket_edges, which likely computes current edges. This makes the tool's role distinct and actionable.

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 the tool—when concerned about edge persistence and decay—by noting that 'a fresh wide edge and a 3-week-old wide edge are different trades.' It provides clear context for the trade-off but does not explicitly name alternatives or exclusions. Since sibling tools are listed but not referenced in the description, the guidance is strong but not fully explicit.

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