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

Beyond the readOnlyHint annotation, the description discloses non-obvious behavioral constraints: a mandatory filter (at least one of campaign_id/asset_id), default scoping to the active Space, and the ability to override with space_id for a single call. These are essential operational details not implied by the annotation alone.

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 description is two sentences with the primary action front-loaded. Every clause contributes a distinct piece of information: the action, the required filter, and Space scoping. No redundant or filler words.

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?

The description covers the essential context: the action, required filter, Space scoping, and override. With 5 well-documented parameters and no output schema, it is mostly complete. A minor gap is that it doesn't describe the return structure or pagination behavior beyond the schema's cursor description, but this is not critical for a list operation.

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 schema already covers all parameters with 100% description coverage, so the baseline is 3. The description adds the crucial cross-parameter constraint that campaign_id or asset_id must be present, which is not reflected in the schema's required field list, and clarifies the space_id override behavior. This adds meaningful value 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?

The description clearly states the specific action ('List asset-to-campaign attachments') and the exact resource relationship, distinguishing it from sibling tools like list_assets and list_ad_assets. The verb 'list' and the resource 'asset-to-campaign attachments' are unambiguous.

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?

It provides explicit context for when to use the tool: at least one of campaign_id/asset_id is required, and it explains Space scoping with a reference to set_active_space and the space_id override. While it doesn't explicitly name alternative tools for different attachment types, the context is sufficient for an informed agent.

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