List nodes

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

Annotations already mark this as read-only (readOnlyHint=true). The description adds context about the specific data returned (role, heap, CPU, load), which goes beyond the annotation. However, it does not disclose any other behavioral traits like performance or pagination.

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?

The description is a single, front-loaded sentence that immediately conveys the tool's purpose and the type of information provided. Every word is useful and there is no redundancy.

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 gives enough context via the equivalent _cat/nodes reference and lists fields. It could be more explicit about the response format (e.g., array of node objects), but for a simple read-only list, it is largely complete.

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?

There are zero parameters, so the baseline is 4. The description does not need to add parameter semantics, but it clearly states the tool lists nodes without any filtering, which is consistent with the empty input 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?

The description clearly states the tool lists nodes in the cluster with specific metrics (role, heap, CPU, load), referencing the equivalent _cat/nodes API. This is a specific verb+resource+info combination that distinguishes it from sibling tools like list_indices or cluster_health.

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?

The description gives a clear purpose but does not explicitly state when to use this tool versus alternatives like cluster_health or cluster_stats. While it implies usage for node-level metrics, no guidance on exclusions or context is provided.

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