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

Goes well beyond the annotations by disclosing no authentication is required, that no image is received or generated, and that image-containing requests are rejected. These are concrete behavioral facts an agent needs and that the readOnly/idempotent annotations do not convey.

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?

Front-loads the purpose, then layers constraints and a sibling reference. Slightly repetitive (text-only restated via 'receives no image and generates no image' and 'keep any photograph in the originating assistant'), but each sentence is largely informative.

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?

With annotations covering the safety profile and no output schema, the description supplies the key constraints (text-only, no auth, image rejection) needed to invoke correctly. Return format is only implied by 'build ... scene context,' leaving a minor gap.

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 description coverage is 100%, so the schema already documents language, request_text, and scene_preference. The description restates the request/preference idea but adds no syntax or format detail beyond the schema; baseline 3 applies.

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 concrete verb (build) and resource (text-only scene context) and clarifies the scope with 'for use in the caller's own image-capable assistant.' It differentiates itself from a sibling by pointing to get_cassie_hour_visual_canon, though the notion of 'scene context' remains somewhat abstract.

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 context (build text-only scene context from a short request) and names the alternative get_cassie_hour_visual_canon 'for general reference.' It does not spell out explicit when-not-to-use conditions beyond the image rejection, but the routing hint is present.

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