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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the 'immutable' property and narrows the resource to candidate email template versions, but it does not disclose return shape, pagination, ordering, or any filtering behavior beyond the schema.

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 extremely brief and front-loaded, with every word contributing to the core purpose. It is easy to parse, though the brevity comes at the cost of useful context about usage and parameters.

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?

There is no output schema, no parameter descriptions, and no usage guidance, and the description does not clarify how this tool relates to the many sibling email-template tools. Given the close siblings and the 0% schema description coverage, this description is not sufficient for an agent to confidently select and invoke the tool without additional inference.

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 0%, so the description must compensate for explaining the parameters, but it does not mention email_type or request_id at all. The schema provides enums and basic types, yet the description adds no meaning about what these parameters do or how they affect the listed versions.

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 clearly identifies the action ('List') and the resource ('immutable candidate email template versions'), which is more specific than the title. However, it does not explicitly differentiate this tool from the similarly named sibling yardstick_email_templates_list or email_drafts_history, leaving some ambiguity about which list to use.

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?

There is no guidance on when to use this tool versus alternatives such as email_templates_list, email_templates_read, or email_drafts_history. The description does not state what distinguishes 'candidate email template versions' from other email template operations, so an agent must infer the appropriate context.

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