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

Annotations already cover idempotency and non-destructiveness, and the description adds one meaningful behavioral rule: overrides must target existing element ids. However, it does not disclose whether existing locale overrides are replaced wholesale or merged, nor does it address state or permission behavior beyond what the schema already implies.

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?

Two sentences with no filler; the first sentence states the operation and scope, and the second provides the critical invariant. The description is front-loaded and every word earns its place.

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?

The required IDs and element-list shape are clear, and the description adds the existing-element rule. However, the actual locale-content fields inside an element are left as arbitrary additionalProperties, and merge/replace behavior for existing locale overrides is unspecified, so the picture is adequate but not fully 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?

All parameters are already described in the schema, so the baseline applies. The description adds one useful semantic constraint about the elements parameter, but it does not add meaning for notification_id, journey_id, locale_id, or state beyond their schema descriptions.

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 uses a specific verb ('Set') and names the exact resource: 'locale-specific content overrides for a journey-scoped notification template'. It also states a key constraint (element overrides must reference existing element ids), which distinguishes it from sibling content-put tools like put_journey_template_content.

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 clearly indicates when this tool is appropriate: for locale-specific overrides on a journey-scoped notification template. It does not explicitly name alternatives or provide exclusion criteria, but the scope language is specific enough for an agent to separate it from the generic content-put siblings.

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