system_logout

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

The description goes well beyond annotations, detailing that there is no true logout, the daemon is not contacted, host config is untouched, the private docker-py attribute is accessed, and it degrades gracefully. This gives the agent accurate expectations for side effects and failure modes.

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 moderately long but every sentence adds value—key facts are front-loaded, and technical caveats are organized in a clear paragraph. The args/returns block makes it scannable.

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 a simple schema and no output schema, the description covers the operation's behavior, return value, edge cases, and internal implementation notes. It is fully self-contained and leaves no important gaps.

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?

Despite 0% schema coverage, the description fully documents the single 'registry' parameter, including its meaning, default (None = all), and the Docker Hub key name ('docker.io'). This is far more than the schema provides.

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: 'Clear cached registry credentials from this server's in-memory Docker client.' It clearly distinguishes itself from siblings like system_login, system_close, and system_reconnect by explaining it only clears the in-memory cache and doesn't contact the daemon.

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?

It explicitly states when to use this tool: to clear cached credentials, and names alternatives (system_login, system_close, system_reconnect) that also clear it. It explains the difference between clearing all vs a specific entry and the key matching requirement, giving the agent clear decision criteria.

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