Update ZeptoMail template

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

Annotations already mark this as non-read-only and destructive. The description adds meaningful guardrail context beyond annotations: stale or wrong-Agent edits are rejected, confirmation is mandatory, and writes must be enabled. This goes beyond what the schema or annotations alone convey.

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 two dense sentences with no filler. The core action is front-loaded, and the critical requirements are stated immediately after, making it easy for an agent to parse and act on.

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, mutation-focused tool with 10 parameters and no output schema, the description covers the key invocation requirements: partial update, single Agent, fresh expected values, writes enabled, and confirmation. It does not describe return values or detailed error behavior, but the lack of an output schema lowers that burden.

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 description coverage is only 10%, so the description must compensate. It usefully explains expectedAgentName and expectedModifiedTime as optimistic-concurrency guards and mentions confirm=true, but it does not clarify the semantics of subject, htmlBody, textBody, templateName, or templateAlias beyond their raw string types.

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 and resource: 'Partially update a template in one explicit Agent.' It distinguishes this from create, delete, get, and export sibling tools by emphasizing partial update and single-Agent scope, so an agent can tell what the tool is for 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?

The description clearly states preconditions: expectedAgentName and expectedModifiedTime must come from fresh reads, writes must be enabled, and confirm=true. It shows when to use the tool but does not explicitly contrast it with related tools or state when not to use it.

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