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

Annotations already declare destructiveHint=false and readOnlyHint=false, and the description reinforces this by stating the result is a new image with an alpha channel rather than an in-place mutation. It also enumerates transformations it explicitly does not perform, which is genuinely useful. It stops short of covering idempotency or any failure modes, but adds real context beyond the annotations.

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 operation, then separates usage and exclusions into distinct paragraphs, with the return noted last. Slightly verbose given the trigger-phrase list, but every sentence maps to a decision the agent must make.

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 an output schema present, return-value explanation is not required, yet the description still notes the alpha-channel result. Combined with clear input constraints and exclusions, an agent has everything needed to 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?

Schema description coverage is 100%, so both parameters and the ContentRef structure are already documented. The description's constraints on the input (image already in the account) duplicate the schema's 'already-uploaded MEDIA content reference' note rather than adding new semantics. Baseline 3 applies when the schema does the heavy lifting.

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 (strip) and resource (image background) and defines the exact outcome: subject on a transparent backdrop. An agent can distinguish it from siblings like generate-image or separate-image-layers without opening the schema.

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 explicit when-to-use triggers (background gone, knocked out, transparent, plus phrasing like cut out, extract, separate), and explicit when-NOT-to-use conditions (not a new scene, does not crop/reframe, replace background, or invent content). This directly routes the agent against plausible alternative intents.

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