login

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

Annotations indicate it's not read-only and not destructive. The description adds critical behavioral context: passwords may be logged verbatim, and credentials can be cached. However, it does not fully explain the caching mechanism or what the response dict contains.

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 well-structured with a clear opening sentence, a security paragraph, and a parameter list. It is front-loaded, but the inclusion of an invalid parameter introduces noise.

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 complexity (security-sensitive authentication with 6 parameters and no output schema), the description omits details about response handling, error scenarios, and credential caching. The parameter inconsistency further reduces completeness.

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?

Schema coverage is 0%, so the description must fully explain parameters. It lists all parameters but includes 'host', which is not in the input schema, potentially causing errors. Descriptions of existing parameters are minimal and lack detail on formats or constraints.

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 clearly states the tool's purpose: 'Authenticate with a Docker registry.' The verb 'authenticate' and resource 'Docker registry' are specific, and it distinguishes itself from sibling tools like 'logout'.

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 provides explicit when-to-use and when-not-to-use guidance, including a security warning about password logging, and recommends running 'docker login' on the host as an alternative. It also advises against calling the tool from an agent loop.

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