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

Annotations already declare the operation as mutating, idempotent, and non-destructive. The description adds the important behavioral caveat that all existing elements are overwritten, plus the channel-targeting structure. There is no contradiction with the annotations.

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 key facts are front-loaded: replace, overwrite, and channel targeting. The multi-channel example is lengthy but earns its place by clarifying the complex nested structure of the elements parameter.

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 example fills the most significant gap for the nested elements structure, and schema coverage handles the remaining parameters. It could be slightly more complete by cataloging allowed element types or explaining version behavior, but the core usage is well covered.

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 100% schema coverage, the parameters are already documented at a basic level. The description goes further by providing a concrete multi-channel elements example that illustrates how channel, meta, and text nodes nest inside the otherwise generic elements array.

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: 'Replace the elemental content of a V2 notification template.' It immediately clarifies scope with 'Overwrites all elements,' which differentiates this from singular-element operations such as put_notification_element.

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 gives a useful in-tool guideline ('Use channel elements to target specific channels') and implies a full-replacement workflow with 'Overwrites all elements.' However, it never name-checks alternatives like put_notification_element or explicitly states when this tool should be avoided in favor of a partial update.

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