fetch_image_downloadFetch a completed project's image as inline MCP image content for compatible clients. Use the exact signed download URL, including query parameters. Requires HTTPS at the configured Magic Hour media host. Read-only; limited to 8 MiB, or a smaller requested max_bytes. Use the signed URL directly for larger files.
| Name | Required | Description | Default |
|---|---|---|---|
| max_bytes | No | ||
| download_url | Yes |
Changes observed during successful MCP inspections.
Input schema / properties / max_bytes / defaultPrevious value: -15728640New value: +8388608Input schema / properties / contextRemoved value: -{
- "description": "Explain in 15-25 words, in third person, why this tool is called and how it supports the user's goal. For analytics only. You MUST describe only the abstract purpose of the tool call. NEVER include, repeat, paraphrase, or infer personal, sensitive, or identifying information from the user request or tool results, including names, emails, phone numbers, IPs, IDs, or credentials. You MUST generalize specific entities into roles such as \"a user\", \"the customer\", or \"an account\". Example: \"Retrieving a customer's recent orders to investigate a billing issue and help support determine the appropriate resolution.\"",
- "type": "string"
-}Input schema / properties / contextAdded value: +{
+ "description": "Explain in 15-25 words, in third person, why this tool is called and how it supports the user's goal. For analytics only. You MUST describe only the abstract purpose of the tool call. NEVER include, repeat, paraphrase, or infer personal, sensitive, or identifying information from the user request or tool results, including names, emails, phone numbers, IPs, IDs, or credentials. You MUST generalize specific entities into roles such as \"a user\", \"the customer\", or \"an account\". Example: \"Retrieving a customer's recent orders to investigate a billing issue and help support determine the appropriate resolution.\"",
+ "type": "string"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds meaningful behavior beyond the annotations: HTTPS media-host requirement, inline-content delivery, an 8 MiB cap or smaller max_bytes, and a fallback for larger files. These constraints materially affect whether the tool can be used successfully.
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 short sentences, front-loaded with the primary action, then constraints and fallback. No sentence is wasted.
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?
There is no output schema, so the description appropriately explains the return as inline MCP image content. Combined with annotations covering safety and the description covering usage limits and parameters, an agent has everything needed to call 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?
With 0% schema description coverage, the description carries the full burden and does so effectively: download_url must be the exact signed URL including query parameters, and max_bytes controls a cap no larger than 8 MiB. Both parameters gain actionable meaning beyond their bare schema types.
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 verb and resource ('Fetch a completed project's image') and specifies the mechanism ('inline MCP image content'). This clearly distinguishes it from fetch_video_download and fetch_audio_download without naming them.
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?
Gives clear operational guidance: use the exact signed URL including query parameters, and use the URL directly for files larger than the inline limit. It does not explicitly name sibling alternatives, but the when-to-use conditions are sufficiently clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.