list_datasources

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

With no annotations provided, the description is the sole source of behavioral information. It conveys that the tool is a read-only operation returning a list, but it does not disclose details such as potential errors, completeness guarantees, or whether the list contains only metadata or full objects. It is neither misleading nor rich, so a midpoint score is warranted.

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 a single, front-loaded sentence with no redundant words. It states the action and the target resource concisely, earning a perfect score for brevity and focus.

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 (zero parameters, no output schema, no annotations), the description provides adequate context for an agent to know what the tool does. It could be more explicit about the return format (e.g., names vs. full metadata), but it remains complete for a basic listing operation.

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 accepts zero parameters, so the schema is empty and the description adds all necessary context. According to the rubric, the baseline for 0 parameters is 4. The description clarifies that no input is needed to list all datasources, which is sufficient.

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 uses a specific verb ('Get') and resource ('list of all available datasources in Druid'), making its purpose immediately clear. It distinguishes itself from sibling tools like execute_sql_query, get_datasource_metadata, and test_connection by virtue of focusing solely on listing datasources.

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 clearly implies when to use the tool: when you need an overview of available datasources. While it does not explicitly exclude alternatives or mention sibling tools, the context is unambiguous. A score of 4 is appropriate because the guidance is implicit but strong; a 5 would require explicit 'when not to use' or named alternatives.

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