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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the cost ($0.03 USDC per call via x402 on Base mainnet) and the exact failure/recovery path for unpaid calls, including where to put the signed payload. This is precisely the operational context an agent needs and cannot get from the schema or 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?

Three sentences, front-loaded with the purpose, then audience, then payment mechanics. No filler and nothing repeated from the schema or annotations.

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 does state what the response contains (new CVEs, advisories, actor activity) and fully covers the payment/auth path. It omits pagination, result-size limits, and accepted sector values, but the core picture needed to invoke it is present.

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%, with both `days` (default 7, max 30) and `sector` documented in the schema. The description's "last N days" only loosely restates the `days` parameter and adds no format, enum, or validation detail beyond it, so the baseline 3 applies.

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?

"What is NEW for a sector in the last N days" states a specific retrieval operation with explicit scope (delta only) and enumerates the returned content types (new CVEs, CISA advisories, actor activity). This clearly separates it from siblings like getSectorBrief and getSectorSitrep, which provide full pictures rather than changes.

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?

"Designed for cron-based monitoring agents" and "Only returns changes" give a clear use context and implicitly frame it against full-summary siblings. It stops short of explicitly naming an alternative (e.g. getSectorBrief) for the non-delta case or stating exclusion conditions.

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