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

Annotations already declare readOnly=false, destructive=false, and idempotent=false, so the safety profile is covered. The description adds useful semantics about what changes (cutout replaced by the original upload), but says nothing about whether the cutout is recoverable, required prior state, or failure modes, so it earns only modest credit 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?

Two short sentences, action first then condition, with zero filler. The reason-to-use clause is front-loaded after the core action and nothing wastes space.

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 2-parameter, non-destructive mutation with no output schema and safety already covered by annotations, the description is nearly complete: it says what it does and when to invoke it. It omits edge behavior such as what happens if the photo has no generated cutout.

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 coverage is 50%: site is documented with its allowed value, but photoId has no description in either schema or description text. The description references "the cutout" and "the picture" without mapping them to photoId, so it does not compensate for the coverage gap. Baseline 3.

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?

"Swaps the cutout back for the picture as uploaded" states a specific action and resource, making clear this reverses background removal rather than deleting (delete_photo) or updating (update_photo) a photo. It does not name any sibling to differentiate against, so it stops short of a 5.

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?

"Use when background removal clipped the product" gives a concrete trigger condition for selecting this tool. It offers no explicit when-not or named alternative (e.g., update_photo), so it is clear context without exclusions.

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