create_upload_url

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

Despite having no annotations, the description fully discloses the tool's behavior: it returns an expiring signed URL, the URL itself carries the auth token ('no auth header needed'), the upload response provides an agent-iris://images/{id} handle, and the tool runs locally in the user's deployment. It even tells the agent that the upload is a separate HTTP POST step, so the tool only creates the URL.

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 dense but efficient, with each sentence adding distinct information: purpose, usage, auth, response, and exclusion. The opening 'Catalog entry.' is slightly cryptic and not fully self-explanatory, costing a point, but the rest is well-organized and front-loaded with the core purpose.

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 zero-parameter tool with no output schema and no annotations, the description is remarkably complete. It covers the full workflow: when to call, what the tool returns, how to upload, what the upload response looks like, how to pass the handle to generate_image, and which cases do not need this tool. Nothing essential is missing.

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 tool takes zero parameters and the input schema is an empty object with 100% coverage, so the description has no parameters to explain. It goes beyond the baseline by describing the returned upload_url and the handling of the upload response, making the workflow clear even though no params exist.

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 opens with a specific verb and resource: 'Create the expiring signed URL needed to upload LOCAL image bytes.' It clearly distinguishes the tool from generate_image by stating hosted http(s) URLs should be passed directly to generate_image instead. The 'Runs in your Kuudo deployment, not here' line also clarifies the execution context.

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?

Explicit when-to-use guidance: 'Use this when you have an image on disk (or raw bytes) to feed into generate_image.' It also provides an exclusion rule: 'Hosted http(s) image URLs do NOT need this — pass them to generate_image directly.' This leaves no ambiguity about which sibling handles which case.

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