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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds only the word 'immutable', which usefully implies versions cannot be altered or deleted, but says nothing about ordering, pagination, or what a version record contains.

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?

One short, front-loaded sentence with no padding, but its brevity comes at the cost of under-specification rather than tight editing.

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?

With no output schema, no parameter descriptions, and no usage context, the definition leaves the agent without enough information to call the tool confidently — particularly around the required email_type format and the purpose of request_id.

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% for both parameters, so the description carries the full burden and fails it. It never mentions email_type (required, with a strict lowercase/underscore pattern) or request_id (likely an idempotency key), leaving an agent to infer both from property names alone.

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 states a verb (List) and a resource (email versions), which is enough to identify a read operation, but 'email versions' is a slightly vague rendering of 'email template versions' and it does not distinguish this tool from siblings like yardstick_email_templates_list or yardstick_email_drafts_history.

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 the many neighboring template tools (read, preview, rollback, publish), nor any stated prerequisite such as needing an existing template.

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