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 describes the scanning process, file types processed, and what gets indexed (table of contents), but doesn't mention potential side effects like system load, file locking, or error handling. It adequately covers the main behavior but lacks operational details that would be helpful for an agent.

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 with three focused sentences: the core action, detailed process explanation, and return value. Each sentence adds distinct value without redundancy. While efficient, the second sentence could be slightly more concise by combining the directory and file type information.

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 tool with no annotations and no output schema, the description provides adequate coverage of what the tool does and what it returns. However, it doesn't explain the format of the returned summary or potential error conditions. Given the tool's moderate complexity (file scanning and indexing), additional operational context would improve 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 zero parameters with 100% schema description coverage, so the schema already fully documents the parameter situation. The description appropriately doesn't discuss parameters since none exist, maintaining focus on the tool's operation and output. This meets the baseline expectation for zero-parameter tools.

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 tool's purpose with specific verbs ('scan', 'extracts', 'saves') and resources ('library folder', 'PDF/Markdown files', 'indexes'). It distinguishes itself from sibling tools like 'search_library' or 'get_library_toc' by focusing on scanning and indexing new/modified files rather than querying existing data.

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 implies usage when new or modified PDF/Markdown files need indexing, but doesn't explicitly state when to use this tool versus alternatives like 'search_library' or 'get_library_toc'. No explicit exclusions or prerequisites are mentioned, leaving usage context somewhat implied rather than clearly defined.

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