download_image

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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose a useful side-effect (parent directories are created automatically) and broad source compatibility, but does not mention return values, error handling, or whether existing files are overwritten. It is adequate but not rich.

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?

Three short sentences with no wasted words. The primary purpose is front-loaded, and each sentence adds a distinct piece of information (what, side-effect, source compatibility).

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 tool is simple, but because there is no output schema and no annotations, the description should explain what the tool returns or how success/failure is indicated. It does not mention the return value or error scenarios, leaving a gap. The description is clear but not fully complete for an agent to invoke without assumptions.

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 50%, with only savePath having a description. The description clarifies the overall function (url to local file path) but does not add specific details about the URL format or constraints beyond what is already implied by the tool name and schema. It compensates partially.

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 downloads any image URL to a local file path, using a specific verb and resource. It also distinguishes itself from the sibling search/get tools by noting it works with images returned from those sources.

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 implies usage context by stating it works with images from any of the above sources, which guides the agent to use this tool when a URL is available. However, it does not explicitly state when not to use it or name alternative tools for other scenarios.

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