hub_repo_info

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

Goes beyond the readOnlyHint/destructiveHint annotations by disclosing that it sends no auth and does not read the Docker credential store, and that private repos fail with 404/401. This is valuable operational behavior not captured in annotations.

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?

Concise and well-structured: one-line purpose, then key behavioral constraints, then args/returns. No redundant sentences, all information earns its place.

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 one parameter and no output schema, the description fully covers the input format, the return value (with key fields), and failure modes. Nothing critical is missing for correct invocation and interpretation.

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 has only a bare `repository` string with 0% description coverage. The description compensates fully by explaining the format with concrete examples ('library/alpine' or 'myorg/myimage'), which is exactly what the agent needs.

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?

States the specific action 'Fetch Docker Hub metadata for a repository' and differentiates from sibling tools by explicitly noting that tag lists belong to `registry_tags` and `hub_tags`, while repo metadata is this tool's job.

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?

Provides clear when-to-use guidance: public repos only, no auth, private repos return 404/401. Also names alternatives for tag lists, so the agent knows when not to use this tool.

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