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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It clearly lists what the guide includes: output contract, exit codes, error codes, and retry guidance, giving the agent a strong understanding of what to expect and when to retry failures.

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?

Two concise sentences front-load the core purpose and key details. Every clause adds meaningful information without fluff or redundancy.

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 tool with one parameter and no output schema, the description fully covers what the tool does, the available modes, and what the returned guide contains. It is complete given the tool's simplicity and the context signals.

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 already provides complete descriptions for the 'mode' parameter with enum choices. The description adds valuable trade-off context ('best for whole directories', 'no Node required') that is not present in the schema, enriching the semantics for parameter selection.

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 provides step-by-step integration instructions for compressing images, with specific details about CLI and HTTP paths. This goes beyond the title and distinguishes it from sibling tools like check_image_supported and get_compression_facts, which serve different purposes.

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 provides guidance on when to use CLI vs HTTP modes, indicating CLI is best for whole directories and HTTP requires no Node. It doesn't explicitly compare with sibling tools, but the use case for this tool is self-contained and clear. Lacks explicit exclusions but the context is sufficient.

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