list_sources

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

With no annotations, the description carries the burden. It does convey that the operation is a read-only list and that health status will be included, which is useful behavioral context. However, it does not disclose any limitations, caching, network dependence, or response details, so it stays at a high level.

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?

A single concise sentence with no filler. The action and target are front-loaded and every word contributes to the meaning.

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?

The tool is low-complexity (no params, no nested objects) and the description sufficiently communicates what will be returned: a list of available free music sources and their health status. Since there is no output schema, it does a reasonable job of setting expectations, although the exact result structure is left unspecified.

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?

There are zero parameters and the schema coverage is 100%, so there is nothing meaningful for the description to add. The schema already completely defines the input surface; the baseline of 4 is appropriate.

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 clear verb ('list') and a specific resource (currently available free music sources) plus an additional distinguishing element (health status). It doesn't explicitly call out sibling tools, but the resource type make it obviously different from song search and playback tools.

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 guidance on when to use this tool versus the sibling tools such as search_song or play_song. The description simply states what it does without hinting at the intended workflow or exclusions, leaving the agent to infer use cases.

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