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

The description goes well beyond the annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint) by detailing response structure (tracked, expired, snapshot_dates), explaining edge_pp_net signedness, revealing that snapshots are written on cache-miss, and stating limitations like the 60-day TTL and daily-close computation. This provides substantial behavioral context that annotations alone do not cover.

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 well-structured with labeled sections (Args, RESPONSE, LIMITS) and front-loaded with the core question. Every sentence adds relevant detail, though it is dense and could be slightly more concise without losing value.

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 there is no output schema, the description completely specifies return values (tracked, expired, snapshot_dates), explains edge_pp_net semantics, covers limitations (TTL, daily closes), and addresses data gaps. It is sufficiently complete for an agent to understand what the tool returns and its constraints.

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 description coverage is 100%, so the baseline is 3. The description's Args section merely restates the schema (days lookback default 14, window snapshot family), adding no new semantics. The RESPONSE section indirectly relates days to 'prior snapshots' but does not add parameter-specific detail beyond the schema.

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: it provides edge persistence and decay telemetry from daily polymarket_edges snapshots, answering 'how long has this edge existed and is it shrinking?'. This specific verb+resource distinguishes it from siblings like polymarket_edges, which focuses on current edges rather than historical persistence.

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 this tool: when you need to understand edge longevity and decay over time, contrasting fresh vs. old edges. However, it does not explicitly name alternatives or provide exclusion criteria (e.g., 'if you only need current edges, use polymarket_edges'). The usage context is clear but lacks explicit alternative guidance.

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