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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the agent knows this is a non-destructive write. The description adds one genuine behavioral detail beyond that: product_ref links to a single product card only when product cards are enabled. It still omits whether saving is idempotent, what happens on a name collision, and any permission requirements.

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?

Two short sentences, front-loaded with the core action and resource, with the conditional product_ref detail following. Nothing is padded or repeated from the 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 mutation tool with 5 parameters, a nested open-ended payload object, no output schema, and no schema descriptions, the definition is too thin. An agent gets no signal on required payload shape, save-vs-update semantics, or connection context handling.

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 5 parameters (including a free-form nested 'payload' object), so the description must carry the load. It explains only product_ref and implicitly template_type; name, payload, and the mctx_v1 connection_context pattern are left entirely undocumented in both schema and description.

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?

Names a specific verb and resource: 'Save a reusable Google responsive search ad template.' That distinguishes it from google_ads_templates_list, google_ads_template_delete, and google_ads_template_reverse_engineer. However, it does not separate 'save' from the sibling google_ads_template_update, so the agent cannot tell create from upsert from that text alone.

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. The description never explains whether this creates a new template, overwrites an existing one by name, or acts as an upsert, nor when to prefer google_ads_template_update over this tool. Only the conditional product_ref clause hints at a usage context.

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