container_prune

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

Annotations already indicate destructive behavior, but the description adds valuable context: running containers are never affected, filter key semantics are explained, and a preview workflow is recommended. This goes well beyond the structured annotations and aligns with the destructiveHint.

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 front-loaded with the core purpose, and every subsequent sentence adds distinct value—scope, preview recommendation, filter details, alternative cleanup path, and return format. It is detailed without being verbose.

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 destructive nature and lack of output schema, the description fully covers behavior, safety, parameter semantics, return value, and alternative tools. The agent has everything needed to invoke it correctly and avoid unintended deletions.

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 only lists 'filters' with no description, while the tool description fully explains the parameter: 'Narrow which stopped containers to remove; omit to remove all stopped' and documents valid filter keys ('until' with RFC3339/duration format, 'label'). This significantly compensates for the 0% schema coverage.

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 opens with a specific verb and resource: 'Remove all stopped containers to reclaim disk space.' This clearly states what the tool does and its outcome, distinguishing it from related tools like container_remove, image_prune, and network_prune.

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 explicitly states when to use the tool ('Only removes containers that are not running'), how to preview before running ('Use container_list(all=True)'), and points to an alternative for broader cleanup ('prune_managed prompt'). This gives the agent clear decision guidance.

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