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

Annotations already declare a read-only, non-destructive operation, so the safety profile is covered. The description adds useful expectation-setting with 'not proven winners — no template has performance data behind it', but it does not describe the response shape, pagination, or ordering behavior for the list.

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?

Three short sentences serve distinct purposes: identifying the resource, describing the template structure, routing to the next tool, and setting expectations. It is front-loaded and free of repetition, though the caveat sentence could be tightened slightly.

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 simple read-only listing tool with one optional parameter and no output schema, the description gives enough context to call it correctly and to understand what a template represents. The main gap is that it doesn't describe the returned template records' fields beyond the high-level structure.

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 100%, and the single language parameter is fully documented in the schema with enumerated codes. The description adds no additional parameter meaning, so the schema does the work and baseline 3 applies.

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 resource (Promptify's ad template library) and explains what a template is, with concrete examples of hook device plus beat structure. The listing verb is implicit in the name rather than stated, but an agent can immediately tell this tool surfaces templates for use elsewhere.

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 actionable context: pass a template's id to generate_ad_script to build an ad on that structure, and it cautions that templates are craft patterns with no performance data. That sets the workflow and expectation, though it does not explicitly state when not to use this tool versus siblings like list_ads or draft_ad_plan.

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