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

The annotation already covers readOnlyHint, and the description redundantly restates "Read-only" rather than adding to it. However, it does disclose a genuinely non-obvious data-model behavior: rows with report_scope 'cluster' and an empty namespace carry node/control-plane images belonging to no namespace, which tells the agent how to interpret and reconcile the result set.

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 resource and scope, followed by output contents, the row-semantics caveat, and the routing hint. The long enumeration sentence is dense but every clause carries real information. Minor waste in the redundant "Read-only" line already covered by the annotation.

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?

No output schema exists, so the description must convey return values — and it does, enumerating the per-row security posture fields and the severity/known-exploited/fixable-severe breakdowns. Combined with the row-semantics explanation, an agent has enough to interpret results correctly without further lookup.

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 100%, so all six parameters (page, sort, order, search, page_size, cluster_id) are already documented and the baseline is 3. The description mentions the cluster restriction implicitly via "or of one cluster" but adds no format, default, or syntax detail beyond the schema.

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 (List), resource (security namespaces), and scope (fleet-wide, or one cluster via cluster_id). It enumerates the exact columns returned (workloads, images, pods, BOM counts, findings by severity) and distinguishes itself from siblings like list_security_pods and list_security_cluster_posture by naming the drill-down relationship.

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?

"A namespace is usually one workflow, so start here before drilling into list_security_pods" gives an explicit entry-point recommendation and names the alternative tool to use next. The cluster-vs-fleet scoping condition is also stated, so the agent knows which mode applies.

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