image_registry_data

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

Annotations `readOnlyHint=true` and `destructiveHint=false` already indicate safe read. Description adds value by disclosing that it uses daemon's cached credentials, warns about logging of `auth_config`, and advises on secure usage. No contradiction.

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?

Description is about 150 words with clear segmentation: main purpose, method details, alternative, security note, then parameter list. Front-loaded with purpose. Slightly wordy but well-structured.

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?

With only two parameters and no output schema, description covers usage, authentication, return type ('Registry data attrs'), and security. Return value description is vague, but adequate for agent to understand the tool's purpose and safe usage.

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?

Despite schema having no descriptions (0% coverage), the description explicitly lists both parameters: 'repository - Image reference' and 'auth_config - Optional registry authentication config.' This fully explains parameter meaning and optionality.

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 'Get registry data for an image without pulling it, via the daemon's distribution endpoint.' Verb 'Get', resource 'registry data', method via daemon. Distinguishes from sibling tool `registry_manifest` by specifying daemon vs direct access.

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?

Explicitly says when to use (via daemon) and when not to: 'For direct registry access without a daemon use `registry_manifest`.' Also provides security guidance on `auth_config` and preference for `docker login`.

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