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

With no annotations, the description carries the full burden. It discloses the need for an API key and the specific data points returned, but does not mention potential error conditions, network behavior, or how OS support is determined.

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?

Two sentences with no fluff; the first sentence front-loads the core functionality, the second adds the authentication requirement.

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 single-parameter tool with no output schema and no annotations, the description covers the main purpose and one prerequisite, but omits guidance on return value details or edge cases, making it minimally sufficient rather than complete.

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 schema provides only a parameter name 'image' with no description. The tool description adds that it refers to a container base image, giving the parameter context, but does not specify expected format (e.g., tag, digest) or provide examples, so meaning is still limited.

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 provides size, last rebuild date, and OS support status for a container base image. This distinguishes it from sibling tools focused on packages, providers, and EOL checks.

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 implies usage for inspecting base image details but does not explicitly compare to alternatives such as check_eol, which may overlap on OS support. The only usage condition mentioned is the requirement for a key, which is a prerequisite rather than a selection guideline.

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