update_settings

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

Beyond the destructiveHint annotation, the description discloses dynamic-only behavior, refusal of static settings, and the required configuration/confirmation gates. This tells the agent not only that mutation occurs, but exactly what preconditions need to be satisfied before it attempts the call.

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 compact and front-loaded. Its first sentence states action and scope, and the remaining sentences cleanly communicate limits and prerequisites. Every clause carries useful information without padding.

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 and the destructiveHint already annotated, the description is sufficiently complete for a moderate update-settings call. Minor gaps, such as specifying how the settings parameter should be serialized and how partial updates behave, keep it just short of perfect.

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?

With 0% schema coverage, the description compensates by naming concrete settings values and making the confirm parameter's requirement explicit. It could additionally clarify the accepted string/object format for the settings argument, but the examples and the static-settings refusal add real semantic value beyond the raw 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 opens with a specific verb and resource: 'Update dynamic index settings', and gives concrete examples like number_of_replicas, refresh_interval, max_result_window, and blocks.*. It also narrows the tool's scope by excluding static settings, so an agent can immediately tell it apart from other index-related siblings.

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 clear usage boundaries: use it for dynamic live-index settings, and static settings will be refused. It also states the prerequisites for invocation, including writes enabled, ES_MCP_ALLOW_DESTRUCTIVE=true, and confirm=true. It does not explicitly name alternative sibling tools, but the dynamic/static distinction and index-settings scope provide strong routing guidance.

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