List Checkpoints

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

With no annotations, the description must convey key behavioral traits. The description notes it's a GET request (implying read-only) and lists the returned fields. It does not mention side effects or prerequisites, but for a simple list operation, this is sufficient. The tip about using model_name/filename adds practical context that goes beyond a mere listing.

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 two sentences, front-loaded with the main action and detailscarsely. No fluff or redundant information; every sentence adds value. The API endpoint is useful for technical clarity.

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 zero-parameter list operation with no output schema, the description is quite complete. It specifies the data returned (title, filename, type, hash), the HTTP method, and the practical usage (use output for sd_model_checkpoint). It doesn't address edge cases like errors or performance, but those are not critical for a simple list tool. It could mention that no parameters are required, but the schema already indicates that.

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 tool has zero parameters, and the input schema has 100% coverage (empty properties). Since there are no parameters to document, the description needs no additional parameter information. The description focuses on the output and usage, which is appropriate here.

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 exactly what the tool does: 'List all registered checkpoint models' with a specific resource and scope. It distinguishes from sibling tools like sdnext_list_loras or sdnext_list_extra_networks by clearly naming the resource type. The inclusion of the API endpoint (GET /sdapi/v1/sd-models) provides an unambiguous reference.

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 mentions the use case: 'Use model_name or filename for sd_model_checkpoint.' This gives clear practical guidance on how to apply the output. However, it does not explicitly state when not to use this tool or compare with alternatives, though the sibling context implies it is the go-to for checkpoint enumeration.

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