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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds the useful fact that the data is local-corpus metadata (counts and timestamps), but says nothing about cost, caching, or how the freshness values should be interpreted.

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?

A single tight parenthetical phrase, front-loaded with the two things it reports. It is efficient, though the verbless fragment form is slightly less self-explanatory than a full sentence.

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 usefully enumerates the returned fields (counts plus latest timestamps), which is exactly what an agent needs to know. A zero-param read-only tool needs little more.

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 tool takes zero parameters, so the schema carries nothing to explain; baseline 4 applies. The description correctly implies a no-argument snapshot call.

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?

Names the resource (corpus) and precisely enumerates the signals returned: CVE/KEV/EPSS counts and latest timestamps. No verb, and it doesn't differentiate from siblings like search_vulns or enrich_cve, but the intent is unambiguous.

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?

There is no statement of when to call this versus alternatives. The agent must infer that this is a pre-flight freshness/metadata check rather than a search tool; nothing in the text guides that choice.

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