Create backing image

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

With no annotations provided, the description carries the behavioral burden. It discloses that creation is destructive, that downloads occur server-side from Longhorn's own network position, and that URLs must be trusted. It could specify more concretely what 'destructive' impacts, but the warning is substantive and actionable.

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?

Four concise, purposeful sentences: the core action, the critical URL behavior, the authorization guardrail, and a doc link. No filler or repetition; safety-critical information is front-loaded early.

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 risky create operation with no annotations and no output schema, the description covers the essential behavioral and authorization context and provides a documentation link. It does not enumerate all sourceType variants, but the schema lists examples and the doc link fills remaining gaps.

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 75%, and the description adds value by explaining the meaning of parameters.url for sourceType 'download' and the trust implication. This goes beyond the schema's generic example and helps the agent construct valid, safe calls.

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 creates a new backing image, which is a specific verb+resource. It does not, however, differentiate from the sibling backingimage_upload or backingimage_backup_create, leaving the exact boundary between create and upload implicit.

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 gives explicit safety guidance: only use a 'download' sourceType URL the user has explicitly provided and trusted, and never call without explicit user authorization. It lacks an explicit comparison to alternatives like upload, but the when-not-to-use guidance is strong.

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