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

Annotations already declare readOnly/openWorld/idempotent/destructive hints, so the bar is lower, but the description adds rich behavioral context: snapshots written on cache-miss, gaps mean no scan that day, history bounded by 60-day TTL, decay computed on daily closes, and edge_pp_net is signed by trade direction. These nuances are not deducible from annotations and are crucial for correct interpretation of the response.

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 well-structured with labeled sections (Args, RESPONSE, LIMITS) and front-loaded with the core purpose. Every sentence provides meaningful information about behavior, return semantics, or limitations. It is not wasteful, but the density of details (especially in the RESPONSE section) could be slightly overwhelming; still, each part earns its place.

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, so the description must fully explain return values, and it does: tracked[], expired[], and snapshot_dates[] are all defined with key sub-fields (trend, decay_pp_per_day, lifespan_days, etc.) and their interpretations. It also covers data availability limitations (TTL, snapshot gaps) and computation basis (daily closes, net slippage). For a telemetry tool of this complexity, the description is complete and self-sufficient.

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% for both parameters, so the baseline is 3. The description goes slightly beyond by explaining that 'days' is a lookback with default 14, and 'window' selects the snapshot family ('1wk'), tying it to the polymarket_edges window families. It also notes max 30 vs schema clamp 2-30, adding practical context. Not a 5 because the schema already covers defaults and ranges; the description adds only modest interpretive value.

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 phrase: "Edge persistence and decay telemetry built from daily polymarket_edges snapshots." It then states the exact question it answers: "how long has this edge existed and is it shrinking?" This clearly distinguishes it 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 implies usage context: use this tool when you need to understand edge persistence over time from snapshots, not for current edge values. It mentions it is built from polymarket_edges snapshots, which hints at the alternative (polymarket_edges) but does not explicitly say 'for current edge values use X.' The LIMITS section provides constraints on when results are meaningful (TTL, snapshot gaps), which helps with interpretation. No explicit exclusions or alternatives are named, so not a 5.

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