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

Annotations declare readOnly/idempotent hints, and the description adds substantial non-obvious behavior: snapshot write timing (cache-miss), gaps meaning no scan, 60-day TTL history bound, decay computed from daily closes net of slippage, and detailed response semantics for expired opportunities. 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 long but every sentence adds value: purpose, args, response structure, and limitations are clearly segmented. The LIMITS section is particularly useful for setting expectations around TTL and computation methodology. No filler or repetition.

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?

With no output schema, the description thoroughly explains the response envelope (tracked[], expired[], snapshot_dates[]), field semantics, and edge cases (cache-miss gaps, TTL, slippage). This is complete enough for an agent to understand what results to expect and how to interpret them.

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 describes both parameters (days with default/clamp, window with enum/default). The description repeats this information without adding genuinely new semantics. Baseline 3 is appropriate because the schema already 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 it provides 'edge persistence and decay telemetry' and answers a specific question ('how long has this edge existed and is it shrinking?'). It differentiates from siblings like polymarket_edges by focusing on temporal tracking rather than raw edge listing, and explicitly contrasts fresh vs. old wide 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 (assessing edge persistence and decay before trading) and even provides a conceptual example ('a fresh wide edge and a 3-week-old wide edge are different trades'). It does not name explicit alternatives or exclusions, but the context is clear enough for an agent to select it appropriately.

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