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

With no annotations provided, the description carries the full responsibility for behavioral disclosure. It gives useful context about discovering slugs and the intended workflow, but it doesn't explicitly state that the operation is read-only, what the response might contain beyond slugs, or any pagination/authorization implications. The guidance is more about when to call than what the tool actually does under the hood.

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 well-structured, leading with the core purpose and then providing critical usage rules. While it is longer than strictly necessary, every sentence serves a purpose—clarifying when to use the tool and when to defer to siblings. The examples ('show me templates', '列出模板') are helpful without being verbose.

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 list operation, the description covers the essential context: what it does, when to use it, and how it relates to `create_diagram` and `create_from_template`. It does not describe the return format, but since no output schema is present and the tool is straightforward, the missing information is not critical. The description adequately prepares an agent to decide when to call this tool.

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?

The schema already provides 100% coverage with a clear description and enum values for the single optional `category` parameter. The description adds no additional meaning about the parameter, but it doesn't need to—the schema is self-explanatory. This is the baseline case where the description is not expected to compensate for any gaps.

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 names a specific verb ('List'), a clear resource ('all available CodePic diagram templates'), and immediately differentiates this tool from the relevant sibling tools ('go straight to create_diagram' and 'before a user-confirmed create_from_template call'). It makes the tool's purpose unmistakable even before looking at 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 explicitly states when to use the tool ('ONLY when the user has explicitly asked to browse, list, or pick from templates') and when not to ('Do NOT call this as a preparatory step'), and it names the alternative (`create_diagram`). It also clarifies the relationship with `create_from_template`, leaving no ambiguity about routing decisions.

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