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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write operation, so the safety profile is covered. The description adds concrete field constraints (25-char link text, 35-char description lines, YYYY-MM-DD dates), but omits operational behavior an agent would want: whether the created asset is auto-attached to anything, whether it requires review/approval, and what happens on duplicate calls given idempotentHint=false.

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?

Purpose is front-loaded in the first sentence, followed by a short explanatory line and a clean Args block. The Returns line slightly duplicates what the output schema already declares, but overall there is no filler.

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 7-parameter mutation with zero schema descriptions, the definition supplies enough to fill the fields correctly, and the presence of an output schema means return values need not be spelled out. The remaining gap is workflow context — that creation and linking are separate steps — which an agent would need to complete the task.

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 the description carries the full burden and does so: all seven parameters are documented with meaning, the required/optional split, character limits and the date format, plus the notable 'numbers only, no hyphens' rule for customer_id. This is meaningfully more than the schema titles provide.

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 and resource ('Creates a sitelink asset') and adds a one-line explanation of what sitelinks are, which implicitly separates it from the other create_*_asset siblings. It never explicitly contrasts itself with create_callout_asset or create_text_asset, so the differentiation is inferential rather than stated.

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?

The phrase 'can be linked to campaigns or ad groups' hints at the create-then-link workflow, but it never says the asset must subsequently be attached via link_asset_to_campaign or link_asset_to_ad_group, nor when a sitelink is preferable to another asset type. Usage is implied rather than guided.

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