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

Annotations declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds extensive behavioral context: it reads from daily snapshots, returns three structured arrays (tracked, expired, snapshot_dates), explains that gaps occur due to cache-miss conditions, and notes that decay numbers are based on daily closes not intraday. No contradictions.

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 fairly long but front-loaded with the core question. It is well-structured, starting with the main purpose, then explaining the response fields, and ending with limits. Every sentence provides meaningful information; no fluff.

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, but the description thoroughly explains the return structure: tracked[] with time-series, first_seen, trend, decay; expired[] with lifespan_days; snapshot_dates[]. It also covers limitations (60-day TTL, gaps, decay calculation). For a tool of this complexity, it 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%, baseline 3. The description adds value by explaining 'days' as lookback with default 14 and max 30 (schema says clamp 2-30), and 'window' as snapshot family with default '1wk'. It also clarifies concepts like snapshot family and how they affect the data, which is not in the schema.

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 the tool's purpose: providing edge persistence and decay telemetry from daily snapshots. It answers the specific question 'how long has this edge existed and is it shrinking?' and differentiates itself from the sibling tool 'polymarket_edges' by focusing on historical evolution rather than current edges only.

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 explicitly explains when to use this tool (to understand edge persistence and decay) and provides a rationale distinguishing fresh vs. old edges. It does not explicitly name alternative tools but implies that for current edges only, one should use polymarket_edges. Limits like 60-day TTL are also mentioned.

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