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

Annotations declare readOnlyHint, openWorldHint, idempotentHint as true, and destructiveHint false. The description adds substantial behavioral context: it reads from daily snapshots with a 60-day TTL, decay numbers from daily closes, snapshot gaps on cache misses, and explains the response structure including tracked, expired, and snapshot_dates arrays with their fields. No contradictions.

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 detailed and well-organized, starting with the purpose then explaining the response structure with labeled arrays. However, it is somewhat verbose and includes information that could be more terse, such as the full breakdown of tracked arrays and their sub-fields. Still, it remains clear.

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 the complexity of the tool (time-series decay analysis) and no output schema, the description fully explains the return format: tracked, expired, snapshot_dates arrays with their fields, and limitations (TTL, gaps). This provides sufficient context for an agent to understand and use the tool.

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% with descriptions for both parameters (days, window). The description adds meaning beyond schema: explains defaults (14 for days, '1wk' for window), constraints (max 30 for days), and the concept of snapshot families ('window family'). This enriches parameter understanding.

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: 'Edge persistence and decay telemetry built from daily polymarket_edges snapshots. Answers 'how long has this edge existed and is it shrinking?'' It uses specific verbs and resources, and distinguishes from siblings like polymarket_edges by focusing on historical trends rather than current 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 provides clear context for when to use the tool: '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).' It also gives default and max values for the days parameter. However, it does not explicitly mention when not to use or list alternatives, though sibling tools are available.

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