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

Annotations cover read-only, idempotent, open-world. The description adds extensive behavioral detail: edge_pp_net is signed (negative = SELL YES), trend categories, decay_pp_per_day computed on absolute value, expired opportunities, snapshot_dates semantics (cache-miss gaps), TTL limits, and reliance on daily closes vs. intraday. 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?

The description is dense but well-structured: a one-sentence definition, an illustrative question, explicitly labeled Args, RESPONSE sections (tracked, expired, snapshot_dates), and a LIMITS section. Every sentence contributes critical information—no fluff. Front-loaded purpose and clear organization justify a high score.

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?

Given the tool has no output schema, the description fully explains return values and edge cases: tracked/expired/snapshot_dates, trend enum, decay calculation, snapshot gaps, TTL limits, and data provenance. It covers all aspects needed for an agent to invoke and interpret results correctly, exceeding standard descriptions.

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 already has 100% coverage with descriptions for both parameters. The description adds marginal context by calling window a 'snapshot family' and restating defaults/max, but adds no significant new meaning beyond 'snapshot family' and slight clarification of clamp range. Baseline 3 is appropriate as 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 the tool's purpose: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' It poses a specific question it answers ('how long has this edge existed and is it shrinking?') and contrasts fresh vs. old edges, distinguishing it from sibling tools like polymarket_edges that likely show current edges.

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 this tool by explaining its unique value ('a 3-week-old wide edge is different trades') and details what it returns (tracked, expired, snapshot_dates). It does not explicitly name alternatives or say 'use this instead of polymarket_edges,' but the context makes the use case clear. Slight deduction for missing explicit when-not-to-use guidance.

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