host_list

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds substantial behavioral detail: the resolved daemon URL semantics, the meaning of `read_only`, `non_destructive`, `tls`, and `default` fields, and the mirror resource. It also discloses the `null` URL behavior for docker-py platform default, going well beyond the annotation hints.

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 information-dense with no filler. It front-loads the primary purpose in the first sentence, then uses a compact paragraph plus a bulleted return format. Every sentence adds value—behavioral nuances, integration with other tools, and return field meanings—without redundancy.

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 tool with an output schema, the description covers all necessary context: source of hosts, single vs multiple resolution, default fallback, and how to use the result with other tools. It even explains the return dict fields and the mirror resource, making it self-sufficient.

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 there are no parameter schemas to clarify. The description compensates by explaining the concept of the `host` argument used by other tools, which gives context for the list. It doesn't need to describe parameter syntax because none exist, but it effectively explains the relevant selection semantics.

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 'List the Docker hosts configured via DOCKER_MCP_SERVER_HOSTS', a specific verb+resource combo that clearly states the tool's function. It further distinguishes itself from daemon-backed tools by explaining how the `host` argument selects from the listed hosts, setting it apart from siblings like `system_ping`.

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 gives clear context by explaining the single-host vs multi-host behavior and how the `default` entry is used when `host` is omitted. It also tells the user how to use the output with other tools ('pass a name as the `host` argument of daemon-backed tools'). It lacks explicit 'when not to use' exclusions, but provides strong situational guidance.

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