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

Annotations already cover read-only, idempotent, open-world and non-destructive traits, so the bar is lower, and the description still adds genuinely non-obvious behavior: a $0.010 cost, a response containing payment instructions for the Saylor endpoint, and no provider account needed. That cost/payment disclosure is the kind of thing an agent cannot infer from structured fields and materially changes invocation planning. It does not describe error or not-found behavior, keeping it short of a 5.

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 short sentences, front-loaded with purpose and followed by scope limit and cost — each sentence earns its place. Slightly clipped phrasing ("Costs $0.010") reads as terse but stays efficient rather than padded.

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 carries the burden of saying what comes back, and it does so field by field (description, status, CVSS, weakness IDs, references). Cost and payment flow are also covered, which is the main non-obvious operational risk. Only the exact shape of the payment-instruction response is left implicit.

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?

There is a single parameter with 100% schema description coverage including a concrete example (CVE-2021-44228), so the schema already carries the semantics and the baseline is 3. The description adds no constraints beyond the schema, though none are really needed for a single free-form identifier.

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?

Opens with a specific verb+resource ("Resolve a CVE") and enumerates the exact payload: published description, status, CVSS metrics, weakness identifiers, vendor/reference links. That level of field-level specificity makes it distinguishable from siblings like get_package_report or get_python_report without opening either schema.

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 exclusion "does not scan a system or prove safety" usefully rules out a plausible misreading (that this is a vulnerability scan), which is real when-to-use guidance. It stops short of naming a sibling alternative for adjacent needs, so it is clear context without full routing.

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