cadlens_refresh_image_url

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

With no annotations provided, the description carries the burden of disclosing behavior. It discloses that the URL is valid for 3600 seconds (expiration) and that it is cheaper than re-fetching the full result, which are meaningful behavioral traits. It does not mention potential errors or prerequisites beyond 'completed job', but the key behaviors are covered.

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 two sentences, front-loaded with the primary action, and directly followed by a cost-saving note and validity duration. Every word contributes to understanding the tool, with no redundancy or filler.

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, single-parameter tool with no output schema, the description covers the essential context: what it does, when to use it, cost implications, and URL expiration. It does not explicitly state the return value (the URL), but this is strongly implied. Minor gaps remain regarding error behavior for non-completed jobs, but overall it is sufficiently complete.

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 0%, so the description must compensate. It does not explicitly explain the job_id parameter, but the name and context ('for a completed job') imply its role. Given the single, self-explanatory parameter, the description adds minimal semantic value beyond what is already evident from the 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 clearly states the tool's purpose: 'Re-fetch the presigned preview-image URL for a completed job.' This specific verb+resource distinguishes it from sibling tools like cadlens_get_result, and the cost comparison 'Cheaper than re-fetching the full result' further differentiates its use case.

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 clear context for when to use this tool: when you need the preview image URL for a completed job and want to avoid the cost of fetching the full result. It implies a usage scenario but does not explicitly state alternatives or exclusions, though the comparison to 'full result' serves as guidance.

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