system_df_tool

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

With no annotations, the description carries the transparency burden. It clearly states that the tool returns disk usage by images, containers, and volumes, which is a useful behavioral detail. However, it doesn't explicitly state that this is a read-only operation (though 'Get' implies it) or mention any potential side effects or permissions, leaving some ambiguity.

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 extremely concise, using two short sentences to convey the core action and output breakdown. It is front-loaded and wastes no words, earning top marks for efficiency.

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, read-only utility, the description adequately covers what the tool does and what it returns. It could be slightly more complete by explicitly stating it is safe/read-only, but that is easily inferred. The presence of an output schema also reduces the need to describe return structure in detail.

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, so the schema is trivially complete. The description adds no parameter-specific information, but none is needed. The baseline of 4 for no parameters applies.

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+resource ('Get Podman disk usage') and further clarifies scope by listing what the disk usage covers (images, containers, volumes). This clearly distinguishes it from sibling tools focused on specific entity lifecycle or system info.

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 tool's purpose is obvious from its name and description, so usage is implied: use this when you need disk usage information. However, there is no explicit guidance on when to prefer this over alternatives (e.g., system_info_tool) or any exclusions, so it doesn't fully earn a higher score.

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