Edit ad group

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

Annotations only declare readOnly=false, destructive=false, openWorld=true, so the description carries real weight and delivers it: list-replacing semantics for context_hints and product_filters, plus an eventual-consistency warning that a list read may be stale and get_ad_group is current. It does not say whether omitted fields are left untouched (partial update) or what happens to the nested product_filters validity, which are meaningful gaps for a mutation tool.

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?

Three compact sentences, front-loaded with the mutable field set, then the exclusion, then the replacement semantics and consistency caveat. No redundant restatement of the title or schema.

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 six-parameter mutation tool with a nested filter array and no output schema, this covers the essentials: what changes, what cannot change, replacement behavior, and read-after-write consistency. The remaining gap is partial-update semantics for omitted fields and the coupling of product_feed_id with product_filters, which is left entirely to the schema.

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 coverage is 50%, so the description compensates where it matters: "replace the whole list" clarifies the merge-vs-replace question for context_hints, which the schema does not state (only product_filters documents this). It says nothing about product_feed_id's requirement, though the schema already covers that, nor about null description semantics.

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 ("Change") and enumerates exactly which fields are mutable (name, description, context hints, product filters) on a named resource (ad group). It immediately delineates the boundary against a sibling by stating it never changes status or bid and pointing to set_bid.

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 gives an explicit when-not (status/bid edits) and routes those cases to set_bid, and it directs the agent to get_ad_group for an authoritative read instead of a list. The guidance is actionable without opening any other schema.

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