DM20 Protocol

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

No annotations are provided, so the description carries the full burden. It discloses that the tool returns a 'formatted list' of PDF and Markdown sources with 'index status and content counts,' which adds useful behavioral context beyond a basic list operation. However, it doesn't mention potential side effects, performance considerations, or error conditions, leaving some gaps for a tool with no annotations.

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 core purpose and followed by additional details on return format. Every sentence adds value: the first defines the action and resource, the second specifies output details. There is zero waste or redundancy.

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 the tool's simplicity (0 parameters, no output schema, no annotations), the description is nearly complete. It explains what the tool does, what it returns, and the types of sources included. For a list operation with no complex inputs or outputs, this is sufficient, though it could slightly improve by mentioning any limitations or prerequisites.

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, and schema description coverage is 100% (since there are no parameters to describe). The description doesn't need to add parameter semantics, so a baseline of 4 is appropriate—it efficiently states the tool's purpose without unnecessary parameter details.

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: 'List all sources in the library with their content summaries.' It specifies the resource (sources in the library), the verb (list), and the scope (all sources). It distinguishes from siblings like 'list_enabled_library' (which likely shows only enabled sources) and 'search_library' (which filters results).

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 context: when you need a comprehensive overview of all library sources, including their content summaries, index status, and counts. It doesn't explicitly state when not to use it or name alternatives, but the context is clear from the description's specificity about returning 'all' sources versus filtered or enabled-only lists.

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