DM20 Protocol

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: it creates the directory if missing (a side effect), opens the system file manager (platform-specific behavior), and returns the absolute path with instructions. This covers the tool's operational impact beyond basic I/O.

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 efficiently structured in three sentences: purpose, behavior, and return value. Each sentence adds essential information without redundancy, making it easy to parse and front-loaded with the core action.

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 tool with no parameters, no annotations, and no output schema, the description provides good coverage: it explains what the tool does, its side effects (directory creation), platform behavior, and return value. However, it doesn't detail error cases or permissions, leaving minor gaps in completeness.

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 0 parameters with 100% schema description coverage, so the baseline is 4. The description appropriately doesn't discuss parameters, as none exist, and instead focuses on the tool's behavior and output.

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 states the action ('Open the library folder') and resource ('where users can drop PDF and Markdown rulebooks'), distinguishing it from sibling tools like 'list_library' or 'scan_library' which are read-only operations. It specifies the exact purpose: opening a specific folder for file management rather than listing or searching content.

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 provides clear context for when to use this tool: when users need to access the library folder to add rulebooks. However, it doesn't explicitly state when NOT to use it or name alternatives like 'list_rulebooks' for viewing existing content, though the purpose implies it's for file management rather than querying.

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