list_structures

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

No annotations are provided, so the description carries the disclosure burden. It usefully states that results include both session-open structures and workspace .nbt files, but it does not explicitly say the operation is read-only or side-effect-free, which would be helpful for an unannotated list tool.

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 extremely short and front-loads the scope, but it is written as a fragment rather than a complete sentence. It avoids waste but is borderline under-specified for an unannotated tool.

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 that the tool has zero parameters, a simple listing purpose, and an output schema that documents return values, the description is largely complete. It only lacks a brief read-only affirmation, which is minor for a list operation.

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 takes zero parameters, so there is no parameter semantics for the description to add. The baseline for a parameterless tool is 4, and the schema is fully covered.

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 identifies exactly what the tool lists: structures open in the current session plus .nbt files in the workspace. It is clear enough to distinguish this from siblings like structure_info or open_structure, though it omits an explicit verb and only implies the listing action via the tool name.

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 explicit guidance on when to use this tool versus siblings such as structure_info or open_structure. The narrow scope implies it is for discovering available structures, but no alternatives or exclusion conditions are stated.

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