Vulnerability Diff

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

Annotations indicate idempotentHint=true but the description says 'Runs a new scan' each call, which is not idempotent. This contradiction is serious. Additionally, readOnlyHint=true conflicts with performing a new scan. The description does not disclose potential side effects like resource consumption or notifications.

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 multi-line docstring that is fairly concise. It includes a returns section that adds value without being overly verbose. Every part contributes to understanding.

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 single-parameter tool with annotations and a described output schema, the description covers purpose, usage, and return format. However, the behavioral contradictions and lack of disclosure about side effects reduce completeness.

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?

Only one parameter 'baseline' is fully described in the schema (100% coverage). The description adds value by explaining that omitting the baseline uses the latest saved report from history, clarifying default behavior.

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 clearly states the tool's purpose: 'Compare a fresh scan against a baseline to find new and resolved vulns.' It specifies the verb (compare/diff), resource (vulnerability scan results), and outcome (new/resolved vulns). This distinguishes it from sibling tools like 'scan' or 'inventory'.

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 explains when to use the tool: when you want to see changes between scans. It provides context that it runs a new scan and accepts an optional baseline. However, it lacks explicit when-not-to-use or alternative tools, though the sibling list implies differentiation.

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