direct_update_ad_text

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

With no annotations, the description carries the full burden. It does disclose that this is a WRITE operation and that allow_write=true is needed to perform the mutation, which is useful. However, it lacks key behavioral details: it does not mention what happens if allow_write is false (e.g., dry run), whether the operation replaces only specified fields or all fields, error behavior, or any rate limits/permissions. The cryptic 'No ₽·— VPN' adds confusion rather than clarity.

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?

The description is concise at one sentence and front-loads 'WRITE', which is good. However, the inclusion of the garbled phrase 'No ₽·— VPN' detracts from clarity and wastes space. It is not fully polished, though it is arguably still efficient.

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?

Given the tool has 5 parameters, a nested 'ads' object, no output schema, and no annotations, the description is insufficient. It does not explain return values, error handling, partial success behavior, or how to construct the ads array correctly. The description fails to provide a complete picture for an agent to safely use the tool.

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?

The description adds meaning to the 'ads' parameter by listing the updatable fields (Title/Title2/Text/Href/DisplayUrlPath/AdImageHash/SitelinkSetId), which are otherwise undocumented in the schema. This partially compensates for the 40% schema description coverage. However, it does not mention 'clear_image', 'dry_run', or explain the 'project' parameter beyond what the schema already states.

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 clearly states the tool's purpose: 'WRITE: ads.update TextAd Title/Title2/Text/Href/DisplayUrlPath/AdImageHash/SitelinkSetId.' This specifies the verb (update), the resource (TextAd), and the exact fields to update. However, it does not explicitly compare against sibling tools like direct_update_ad_href, so it lacks explicit sibling differentiation.

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 description provides minimal guidance on when to use this tool. It mentions 'allow_write=true' as a requirement and 'optional moderate_after', but does not explain when to prefer this over alternatives such as direct_update_ad_href or direct_add_ads. There are no exclusions or explicit alternative recommendations.

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