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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context by listing the exact return fields (id, display name, category, animated video support, Pro requirement) and the two template categories, which goes beyond what annotations provide.

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 sentences, each earning its place: the first defines the resource and gives examples, the second lists return fields, and the third gives usage guidance. The main purpose is front-loaded and there is zero filler.

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?

Given the low complexity, a single optional parameter, and the presence of an output schema, the description is complete. It explains the resource scope, return fields, and usage guidance, so an agent can invoke the tool correctly without additional context.

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 category parameter is already well documented. The description adds value by giving concrete examples for each enum value ('messaging apps (for example WhatsApp, iMessage...) and AI chat apps (for example ChatGPT...)'), making it easier for an agent to map the filter to real-world contexts.

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 ('Lists') and names the resource ('chat templates Mimicly can fill in'), then categorizes them into messaging and AI chat apps with concrete examples. It clearly distinguishes this tool from its only sibling by explicitly saying it is used to determine which template id to pass to create_chat_mockup.

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 gives explicit when-to-use guidance: 'Call it when you are not sure which template id to pass to create_chat_mockup.' It names the alternative tool directly, which is all that is needed given the single sibling context.

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