hub_rate_limit

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, but the description goes further by exposing the mechanism (HEAD request, not metered), header reading, credential fallback, and the fact that it does NOT read ~/.docker/config.json. This is rich, valuable context beyond 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?

The description is well-structured: starts with the core purpose, then explains the mechanism, use case, credentials, and return format. Every sentence adds new information; no redundancy or fluff.

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 description covers the use case, authentication behavior, edge cases (unlimited plans referencing headers), and explicitly lists the return keys. Despite no output schema, the agent knows exactly what to expect. This is complete for a simple, read-only checker.

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% (only names/defaults), so the description must compensate. It does so by explaining each parameter: username overrides DOCKER_MCP_SERVER_REGISTRY_USERNAME, password overrides DOCKER_MCP_SERVER_REGISTRY_PASSWORD. This gives meaning beyond the raw schema.

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 uses a specific verb and resource: 'Report the caller's remaining Docker Hub pull-rate-limit budget.' This clearly differentiates it from sibling tools like image_pull or registry_tags, with no ambiguity about what it does.

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 gives explicit guidance: 'Call it before a large compose_pull / image_pull to avoid hitting the cap mid-deploy.' This tells the agent exactly when to use it, and the context around credentials and metering helps decide whether to supply args.

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