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

Annotations already cover read-only/idempotent/destructive=false, but the description adds substantial context beyond them: a 20-result cap, explicit source capture dates and withdrawals, EPSS/KEV preview content, fix boundaries, and the critical caveat that no results never mean safe.

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?

Core purpose and parameter rules are front-loaded, followed by return behavior and caveats, so nothing is buried. It is dense and clause-heavy, and 'Free and read-only' partially restates the annotations, but nearly every sentence earns its place.

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 must describe returns, and it does so thoroughly: match count, route IDs, capture dates, withdrawals, preview composition, and score caveats. An agent has enough to call it and interpret the output.

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 0%, so the description must carry the load, and it does: it defines the advisory_id-or-ecosystem+package combination rule and explains cursor as continuing the same lookup. It omits format/length details, but the usage relationships are the meaningful part.

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 names a specific verb (look up) and resource (known advisory ID/alias, or ecosystem + package name) within a scoped collection (frozen OSV). It is readily distinguishable from siblings because it explicitly routes results to preview_evidence_answer.

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?

It gives a clear input rule ('Supply advisory_id OR both ecosystem and package') and states cursor's continuation role, plus explicit exclusions ('No range solving, current scanning, independent verification or payment'). It does not explicitly contrast with find_evidence_questions, so it stops short of full alternative routing.

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