list_sa360_custom_columns

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is fully covered structurally. The description adds nothing beyond that — no mention of pagination, remote-fetch latency implied by openWorldHint, or whether the result is scoped to one customer only.

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?

A single short sentence with the resource front-loaded and zero filler. It is efficient, though the terseness contributes to the specification gaps noted elsewhere rather than resolving them.

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?

An output schema exists, so return values need not be explained, but for a three-parameter tool with ambiguous identity parameters and distant siblings, the description leaves the agent without enough to call it confidently. It should minimally clarify the customer_id/login_customer_id roles and the scope of the listing.

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 all three parameters (account, customer_id, login_customer_id) are undocumented. The description doesn't explain the distinction between customer_id and login_customer_id (a non-obvious SA360/Google Ads manager-account concept) or what 'account' selects, so it fails to compensate for the schema gap.

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 names a specific verb and resource ('List custom columns') scoped to an SA360 customer, which is clear enough to understand the operation. It does not distinguish itself from nearby siblings such as search_sa360_fields or query_sa360, which could also plausibly surface column metadata.

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?

There is no statement of when to use this tool versus search_sa360_fields or query_sa360, nor any prerequisite or exclusion. The agent must infer the selection context entirely.

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