system_login

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

Annotations confirm it is neither read-only nor destructive. The description adds critical security context about password logging, a behavioral trait beyond annotations. However, it does not clarify whether credentials are cached or if the tool modifies local state.

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 concise opening, a security warning, and a clear args list. It is front-loaded and efficient, though the args list could be formatted more compactly.

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?

The tool has 6 parameters and no output schema. The description covers purpose, security, parameter semantics, and return type. Missing details about response structure, but overall sufficient for an authentication tool.

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?

With 0% schema description coverage, the description compensates by listing all parameters with brief explanations (e.g., username, password, registry default). The return type is vaguely described as 'dict', which is acceptable but lacks detail.

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 authenticates with a Docker registry, providing a specific verb and resource. It distinguishes from siblings via security warnings and alternative methods.

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 advises against use in agent loops due to password logging, and recommends using 'docker login' on the host as a safer alternative. This provides clear when-to-use and when-not-to-use guidance.

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