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

The description adds substantial behavioral detail beyond the annotations, including how snapshots are generated ('snapshots are written when polymarket_edges runs on a cache-miss'), the TTL constraint ('60-day snapshot TTL'), and the computation method ('decay numbers come from daily closes of edge_pp_net... not intraday'). It also explains the response structure. This goes well beyond readOnlyHint and other 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 structured with clear labels ('Args:', 'RESPONSE:', 'LIMITS:'), making it scannable despite its length. Each sentence contributes meaningful information about usage, response structure, or limitations, with no filler or redundancy.

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?

Since there is no output schema, the description fully specifies the return value structure (tracked[], expired[], snapshot_dates[]) and the semantics of each field. It also covers edge cases like snapshot gaps and the TTL limit, making it a complete reference for the tool's behavior.

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?

The schema already provides full parameter descriptions (coverage 100%), so the baseline is 3. The description's 'Args:' section restates the schema's defaults and adds the term 'snapshot family' for window, but does not provide additional syntactic or format detail not already present in the schema. Therefore, it adds marginal 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 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots,' which clearly identifies the tool's function: tracking edge persistence and decay over time. It goes beyond the title by explaining the specific question it answers ('how long has this edge existed and is it shrinking?') and distinguishes it from both polymarket_edges (current edges) and other sibling tools by focusing on historical persistence and decay.

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 provides a concrete scenario: 'a fresh wide edge and a 3-week-old wide edge are different trades (the latter is wide for a reason nobody is willing to take),' illustrating when the tool is valuable. It also explains the limits of history depth, but does not explicitly state when to use alternatives, so while context is clear, exclusions are absent.

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