source_list

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

With no annotations provided, the description carries the disclosure burden. It adds useful behavioral context beyond the title: the storage location (~/.solo/sources/), that sizes are shown, and that YouTube sources include a videos/video_chunks breakdown. The verb 'List' strongly implies a read-only operation, though it does not explicitly state side-effect safety.

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 three short sentences with no filler. The opening sentence gives the primary purpose, and the following sentences add specific and relevant details about location, sizes, and YouTube-specific fields. It is front-loaded and every sentence earns its place.

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 no-argument list tool with an output schema present, the description is complete: it states what is listed, where the data comes from, what measurements are included, and the special case for YouTube sources. No additional context appears necessary for an agent to select and invoke the tool correctly.

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 input schema has zero parameters and schema coverage is 100%, so there is no parameter documentation burden. The 0-parameter baseline of 4 applies; the description adds no parameter meaning because none is needed.

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 a specific verb ('List') and resource ('indexed external sources') and adds a document-count detail. It further clarifies scope by specifying all source graphs under ~/.solo/sources/, which distinguishes it from sibling tools like source_search, source_tags, and source_related as a global enumeration rather than a filtered query.

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 use when an overview of all indexed sources and their sizes/document counts is needed, but it does not explicitly say when not to use it or name alternatives. There is no explicit routing guidance against sibling tools, so the agent must infer the usage boundary from the word 'List' and the scope detail.

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