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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds a genuinely useful trait beyond them: the verdict is empty for a few seconds after a scan completes, warning the agent about an eventual-consistency window that would otherwise cause confusion.

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?

Two sentences, front-loaded with the returned content, then usage, then parameter. The middle clause is a dense list but every element is informative; nothing is padded or redundant.

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 an output schema present the description need not explain return values, yet annotations cover safety and the description covers the timing caveat and the ID format. What remains missing is any note on failure behavior for an unknown or expired scan_id.

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% with a single parameter, so the description must compensate, and it does: 'scan_id is the UUID of a ScanMalware scan' supplies both the expected format and the system of origin. It adds no edge-case or error semantics for malformed/nonexistent IDs.

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?

States a specific verb and resource ('Get a compact summary of one scan') and enumerates the exact fields returned, so an agent knows precisely what it gets back. The word 'compact' plus 'first look at a scan' distinguishes it from heavier siblings like get_scan_result, get_scan_reports and get_scan_ioc.

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?

'Useful as the first look at a scan' gives clear positioning: a cheap entry point before drilling into detailed result tools. It does not name a specific alternative or state when-not-to-use it, so it falls short of full routing guidance.

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