Get source freshness

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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds specific behavioral detail by listing the output fields and implying no side effects. It doesn't explicitly state that no fetch is triggered, but the read-only annotation covers that safety profile.

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 a single, front-loaded sentence that immediately states the action and the key outputs. There is zero wasted wording, and every phrase adds value.

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?

For a simple, no-parameter status tool with a full output schema and strong annotations, the description is fully sufficient. It names all the relevant data points and does not require additional caveats or prerequisites. The sibling tools make the use case obvious.

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 schema has zero parameters, so the description need not explain parameter behavior. The output-schema covers return values. The description adds no parameter meaning but there is nothing to explain; a baseline of 4 is appropriate for zero-parameter tools.

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 uses a specific verb 'Return' and clearly specifies the resource: 'vulnerability source' status. It enumerates the exact data returned (last fetch state, source timestamp, record count, error summary, stale flag), making it distinct from sibling tools that handle refresh/sync operations.

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 implies the tool is for inspecting freshness/status of vulnerability sources rather than performing updates. It lacks explicit exclusion of alternatives (e.g., 'use vuln_refresh_vrt to trigger a refresh'), but the naming and returned fields give clear context for when it should be used.

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