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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the bar is lower. The description adds that each result carries a known-signature match flag and that shared JARM is weak evidence, but it says nothing about result volume, pagination, or error behavior on an invalid 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?

Three short sentences, front-loaded with what is returned before the interpretive caveat and the parameter note. No sentence is wasted, though the caveat could be tighter.

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 return shape needn't be described, and the one parameter is defined. Safety is covered by annotations. The definition is nearly sufficient for correct invocation, with only the sibling boundary (search_by_jarm) 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?

The single parameter has 0% schema description coverage, so the description must carry the load. 'scan_id is the UUID of a ScanMalware scan' supplies both the format (UUID) and the referent (ScanMalware scan), adequately compensating for the gap.

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 names a specific verb and resource ('Get the JARM TLS server fingerprints') and scopes it to 'the hosts in one scan', which meaningfully distinguishes this per-scan retrieval from the sibling search_by_jarm pivot. It stops short of naming that sibling explicitly, so an agent must infer the boundary.

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?

It offers an analytic caveat ('a weak pivot on its own'), which implies how much weight to give the result, but never states when to call this tool versus search_by_jarm, get_jarm_stats, or get_tls_details. Usage is implied rather than directed.

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