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

No annotations are present, so the description carries the full behavioral burden. It discloses that the URL is temporary, valid for 1 hour, requires no authentication, and costs almost zero tokens, plus it gives practical usage examples. This is substantial, useful disclosure beyond the tool name and schema.

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 front-loaded with the core purpose and key details, then uses concise bullet points for use cases, and ends with an explicit alternative. Every sentence adds value and the structure 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 single-parameter tool with no output schema, the description provides selection guidance, access semantics, expiration, cost, and rendering examples. An agent has everything needed to decide to use it and invoke it correctly.

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 describes file_id as 'The UUID of the file' with 100% coverage, so the description adds little on parameter semantics. The description does reinforce that the tool works for images/files, but it doesn't add format, source, or usage details for the UUID beyond the schema. Baseline 3 is appropriate.

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?

States a specific action ('Get a temporary presigned URL') and resource ('image/file'), and explicitly distinguishes itself from the sibling get_image by noting that get_image is for vision analysis. The purpose is immediately clear and unambiguous.

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?

Explicitly positions this tool as the DEFAULT way to access images, lists concrete use cases, and gives an explicit when-not: 'Only use get_image instead when you need to ANALYZE image content with vision.' This is ideal routing guidance for an agent.

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