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

Annotations already declare readOnlyHint/idempotent/non-destructive, so the safety profile is covered. The description adds useful context beyond annotations: it emphasizes CURRENT assets, lists the returned fields, and defines the empty-campaign_id fallback scope.

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 verb and scope, then adds the two behavioral clauses in a compact form. The long parenthetical asset list is dense but functional, and there is no redundant filler.

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 values needn't be explained, and the scope plus campaign_id fallback are covered. Only the customer_id parameter lacks documentation, a minor gap for a simple two-parameter list tool.

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 0%, so the description must carry parameter meaning. It explains campaign_id well ('if empty, covers all campaigns') but says nothing about customer_id, leaving one of two parameters undocumented.

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?

Opens with a specific verb ('Lists') and resource ('a campaign's CURRENT extension assets') and enumerates the concrete asset types returned. It is clearly distinguishable from sibling write tools like manage_extension_assets and remove_extension_assets, which mutate the same resources.

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?

Explains the practical reason to call it ('the asset id and the resource_name needed to remove each one'), which implicitly routes to the removal workflow. It scopes behavior via campaign_id, but does not explicitly name alternatives 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.