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

readOnlyHint already establishes the safe-read profile, so the description's added value is the filtering behavior it discloses: archived (parked) clusters are excluded from unfiltered listings and only appear via state='archived' or name lookup. That default-exclusion semantic is genuinely useful context beyond the annotation, though permissions and pagination are unaddressed.

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?

Four sentences, each carrying distinct payload (what it returns, when to use, scoping guarantee, archived-filter caveat), with the core purpose front-loaded. Efficient overall, though the trigger list and the archived caveat could be marginally tighter without loss.

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 no output schema, the description correctly compensates by naming the returned fields, and its archived-cluster caveat covers the main edge case for a list tool with an all-optional filter schema under a readOnlyHint. What remains missing — whether results are paginated or sorted — is minor for this operation.

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 the baseline is 3, but the description adds meaning the schema lacks — that the default listing silently omits archived clusters and that state='archived' is the way to surface them. This directly clarifies the effect of the state and name parameters rather than restating their definitions.

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?

Clear verb+resource ("List all clusters") followed by the specific fields returned (state, environment, Kubernetes version, resource counts). It is unambiguous about what the tool does, but it never names or contrasts against close siblings like cluster_query, cluster_search, cluster_describe, or get_cluster_details, so differentiation is left to inference.

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?

Gives concrete when-to-use triggers ("asks how many clusters they have, wants to see all their clusters, or needs to find a specific cluster") and notes it works with no cluster selected. However, it offers no when-not-to-use guidance and does not route the agent to alternatives, which matters given the several cluster-listing/lookup siblings.

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