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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so safety is covered. The description adds value by disclosing that include_detailed_events toggles inclusion of individual events. It says nothing about permissions, rate limits, or behavior on a missing/unknown scan_id.

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?

Front-loaded with the fetch purpose, then parameter semantics; three tight sentences with no filler. The return-field enumeration is somewhat dense but is the tool's key differentiator.

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?

An output schema exists, so return-value explanation is not strictly required, yet the description summarizes it anyway. Combined with annotations and the parameter notes, an agent has what it needs to invoke the tool, and only the sibling differentiation is underdeveloped.

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 coverage is 0%, so the description must carry the burden, and it does: scan_id is documented as the UUID of a ScanMalware scan, and include_detailed_events is explained as adding the individual events. It omits any type/default detail for include_detailed_events, but both parameters are meaningfully covered.

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 and enumerates the returned fields (overall risk, risk scores, script count, eval/Function calls, high-risk events, behavioural signature, composite hash). Very clear about what it fetches. It does not, however, distinguish itself from close siblings like get_js_runtime_coverage, get_js_runtime_health, or get_js_runtime_stats.

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?

Adds useful context that scan_id is the UUID of a ScanMalware scan, which implies usage after a scan. But there is no explicit when-to-use vs. alternatives or exclusion criteria, so the agent must infer from the name which of the several get_js_runtime_* tools to pick.

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