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

With no annotations, the description discloses that processing happens in the browser and consumes more credits than other workspaces, plus restrictions on welcome credits and Day Pass. It adds operational context but does not describe compression behavior (e.g., quality loss, supported formats) or return details.

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 first sentence is concise and purposeful, but the remainder consists of several sentences about credit policies and pricing that could be shortened. It is not excessively long but includes details not directly related to core tool behavior.

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 no-parameter, no-output-schema tool, the description provides enough to understand the main purpose and important usage constraints (credit costs, plan exclusions). It lacks technical details about the compression process, but given the tool's simplicity, it is reasonably complete.

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 input schema has zero parameters, so there is no parameter-specific information needed. The description adds nothing about parameters, but the baseline 4 applies for zero-parameter tools.

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 'Compress Video — Reduce video file size,' which clearly states the specific action and resource. It distinguishes this tool from siblings like video converter or enhancer by emphasizing size reduction.

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?

The description implies usage when video file size reduction is needed and includes credit-related caveats about plan coverage. However, it does not explicitly compare with alternative tools or state when not to use it.

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