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

Annotations already flag destructiveHint=true and idempotentHint=true; the description adds substantive context on top by explaining that the call "replaces the whole design" and that it is rejected for templates modified downstream in Mailercloud. It does not cover authorization or what a dry_run preview returns, which keeps it short of a 5.

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?

Front-loads what the tool does and the replacement semantics before the precondition and dry-run advice. Four sentences, all relevant, though a slightly denser phrasing would carry the same content.

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?

For a destructive, nested-payload mutation with no output schema, it covers the payload model, the replacing behavior, preconditions and preview. It omits any mention of category_id, which is a documented parameter the description never acknowledges.

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; the description earns extra by explaining that the email must be the full rebuilt design ("built the same way as for create_dnd_email_template... never HTML") and that dry_run checks without saving. category_id and template_id semantics are left entirely to the 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?

Uses a specific verb ("Revise") with a precisely scoped resource ("a drag-and-drop template that create_dnd_email_template saved"), which separates it from update_template and from the create sibling. An agent can identify the operation without opening the schema.

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?

States the trigger ("changes the user asks for after saving") and an explicit precondition with alternatives: it only works if the template "hasn't been edited in Mailercloud since it was saved; otherwise make the change in Mailercloud's drag-and-drop editor or create a new template." It also names dry_run as the preview path.

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