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

Annotations already declare readOnly=false, destructive=false, idempotent=false and openWorld=true, so the safety profile is covered. The description adds real value beyond that: the creator plan's kit limit is a hard constraint, and it states the call returns the complete created kit.

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 tight sentences: the capability and its flexible inputs come first, the constraint and return behavior follow. No filler, no restatement of the title.

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?

Annotations supply the safety profile, the output schema means return values needn't be explained (though the description helpfully notes it returns the full kit), and the schema fully documents the 19 fields. Combined, an agent has nearly everything needed to call this 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 the schema documents all 19 parameters, establishing a baseline of 3. The description adds only a light gloss (rates/portfolio optional, template must be listed) and no extra syntax or format detail beyond the schema.

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 and resource ('Create a new creator-owned media kit') and scopes what it accepts (profile content, optional rates/portfolio, design template). The create-vs-update distinction from siblings like media_kit_update is implicit, but no sibling is named, so it stops short of explicit differentiation.

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 the create-new use case and notes the plan kit-limit constraint, but never states when to prefer this over alternatives such as media_kit_ensure or media_kit_duplicate. Usage is only inferable.

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