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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, but the description adds significant behavioral context beyond that: the feed cannot return events before the archive started, it reports coverage.archive_since and rating_actions_recorded, and it costs $0.001 USDC per call via x402. These are valuable operational details with no contradiction.

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 four sentences, each contributing essential info: what the feed is, event types, when to use it, a key limitation, and cost. No filler or redundancy, and it is front-loaded with the core purpose.

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 one optional parameter and no output schema, the description covers the main aspects: purpose, event types, usage guidance, limitation, response fields, and cost. It does not detail the exact structure of each event, but for a feed with these listed event types it is largely complete. A bit more about return format would push it to 5.

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 only parameter 'since' has 100% schema description coverage, with the schema explaining format, default, and archive behavior. The tool description mentions 'since a date' but adds no extra semantics beyond the schema. Per rubric, high schema coverage yields baseline 3.

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 what the tool does: provides a chronological feed of rating actions with specific event types (grade upgrades/downgrades, payTo wallet changes, listing removals, returns). It distinguishes from siblings by emphasizing monitoring a portfolio for adverse changes rather than re-scoring each one, which separates it from scoring/estimation tools.

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 an explicit use case: 'Use this to monitor a portfolio of endpoints for adverse changes rather than re-scoring each one.' This provides clear context and a rationale, though it does not explicitly name alternative tools or say when not to use it. The limitation about archive start is also useful guidance.

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