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

Annotations already declare destructiveHint=true, non-read-only, and closed-world, so the safety profile is conveyed structurally. The description adds only the 'AdsAgent-owned' ownership constraint; it does not say whether the update is a partial merge, what happens to omitted fields, or which values can be overwritten.

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 front-loaded sentence with no filler, so there is no waste. But it is under-specified rather than genuinely concise for a 7-parameter mutation tool.

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 destructive, seven-parameter mutation with no output schema and 0% schema descriptions, the description is far too thin. Fields, merge semantics, prerequisites, and the distinction from product_card_save are all missing.

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% across 7 parameters (including nested objects like decision_rules and connection_context), and the description supplies no field-level meaning. It neither explains merge_keys, funnel_events, nor the required card_id, so it fails to compensate for the coverage 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?

States a specific verb (Update) and resource (product-card metadata) plus a scope qualifier (AdsAgent-owned), which is clearer than a bare tautology. However, it does not distinguish itself from the close sibling google_ads_product_card_save, leaving the save-vs-update boundary to inference.

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?

No when-to-use guidance is given: nothing says when to call update versus product_card_save, product_card_delete, or product_card_cards_list. An agent only learns the card must already exist and be AdsAgent-owned by implication.

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