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

Annotations already declare readOnly/openWorld/idempotent, but the description goes well beyond by explaining data gaps ('snapshots are written when polymarket_edges runs on a cache-miss'), the 60-day TTL limit, and that decay numbers come from daily closes, not intraday. It also details the response structure (tracked/expired/snapshot_dates), providing rich behavioral context that annotations cannot convey.

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: purpose first, then args, response format, and limits. Every sentence carries meaningful information, and the format guides the reader through complex telemetry concepts without waste. The length is appropriate given 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 fully specifies the response shape (tracked[], expired[], snapshot_dates[]) and explains key fields like trend, decay_pp_per_day, and lifespan_days. It also covers data limitations (TTL, cache-miss gaps) and the meaning of negative edge_pp_net. This is complete for an agent to select and interpret the tool's output.

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 are already documented with defaults and constraints. The description adds the concept of 'snapshot family' and restates the lookback window, but does not provide examples or additional semantic nuance beyond what the schema already offers. This meets the baseline for high schema coverage without adding significant 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+resource: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots.' It then answers a concrete question ('how long has this edge existed and is it shrinking?') and distinguishes from siblings like polymarket_edges by focusing on history/decay rather than current edges. This is unambiguous and differentiates the tool.

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 gives clear context: a fresh wide edge and a 3-week-old wide edge are different trades, implying this tool is for evaluating edge persistence before acting. It also frames the median lifespan as a competition clock. However, it does not explicitly name alternative tools or state when not to use this tool, so it stops short of full when/when-not guidance.

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