container_diff

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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description adds critical behavioral context: it compares only the writable container layer, excludes volumes/bind mounts, and documents the return format (list of dicts with Path and Kind values). This goes well beyond the annotations and fully discloses behavior.

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 compact and well-structured: an opening purpose sentence, a usage and limitation sentence, then clear args/returns sections. Every sentence earns its place, and the formatting makes it easy to scan.

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 simple read-only tool with one parameter and no output schema, the description is complete. It covers purpose, when to use, behavior, parameter semantics, and return format including the meaning of Kind values. No significant gaps remain.

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 property has no description (0% coverage), but the description includes an explicit 'args: id_or_name - The container id or name' line. This fully explains the single parameter's meaning, fully compensating for the empty schema description and adding value 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 begins with a specific verb and resource: 'List filesystem changes a container has made relative to its image.' This clearly distinguishes it from sibling tools like container_commit or container_archive_get, and the additional note about only comparing the writable layer reinforces its unique role.

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 states when to use it: 'Use it to audit what a container wrote before `container_commit` or `container_archive_get`, or to debug unexpected writes.' It also gives a when-not by noting that files in volumes and bind mounts never show up, which is a clear exclusion.

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