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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description goes well beyond this by disclosing response structure, decay computation details, snapshot gap behavior, and the 60-day TTL limitation. These are valuable behavioral nuances not derivable from 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?

Though long, the description is well-structured with clear sections (Args, RESPONSE, LIMITS) and is front-loaded with the core purpose. Every sentence adds substantive information about behavior or output, and the format makes it easy to parse.

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 fully describes the response fields (tracked[], expired[], snapshot_dates[]) and their meaning. It also covers data availability limitations, snapshot TTL, and computation caveats, making it complete for an agent to decide and invoke the tool correctly.

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%, so baseline is 3, but the description adds useful context: 'days' is explained as lookback with default and max, 'window' is called a 'snapshot family' and tied to the cache-miss snapshot mechanism. This helps the agent understand the meaning behind the parameters beyond their raw names.

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 function: tracking edge persistence and decay from daily polymarket_edges snapshots. It distinguishes itself from siblings by focusing on historical persistence ('how long has this edge existed and is it shrinking?') rather than current edge lists.

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 for when to use the tool: when you need to know whether an edge is fresh or decaying, and how long it has persisted. It does not explicitly name alternatives like polymarket_edges, but the relationship to snapshots and the decision heuristic ('a fresh wide edge and a 3-week-old wide edge are different trades') imply the intended use case strongly.

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