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

With only readOnlyHint provided, the description adds meaningful behavior: semver ordering, the exact return contents (latest version, ordered list, registries, pinned draft version), and a subtle conditional return detail. It does not contradict the annotation and goes well beyond it.

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 tightly written sentences, front-loaded with purpose and return behavior. Every sentence contributes: ordering, output contents, usage guidance, and sibling differentiation.

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 read-only list tool with full schema coverage and no output schema, the description supplies the needed return details and usage context. Nothing an agent needs in order to call it correctly is missing.

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 100%, so chart_name, cluster_id, and registry_name are already fully documented. The description adds only general context ('one Helm chart', 'registries that carry the chart') without new parameter-level constraints or format details.

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 states a specific verb and resource ('List the available catalog versions for one Helm chart') and adds scope ('newest first, semver ordering'). It explicitly distinguishes itself from the sibling list_available_charts, which only shows the latest version.

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 names concrete use cases: picking an upgrade target before update_addon_config and verifying that a requested chart_version exists. It also contrasts with list_available_charts, making the alternative condition explicit.

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