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

The description adds meaningful context beyond annotations: it states 'Permanently deletes the resource. Irreversible.' and explains the Space scoping behavior. The annotations already mark destructiveHint=true, so the description's value is in reinforcing the permanence and providing the scoping detail.

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 tightly written: three short sentences that each carry essential information. No filler, and the most important fact (permanent deletion) is front-loaded.

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 simple deletion tool with annotations and only two parameters, the description fully covers purpose, risk, and the active-Space behavior. There is no output schema expected, so no missing return information. The description is sufficient to invoke the tool correctly.

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 schema already provides a detailed description for space_id, and the description reinforces its behavior and default. However, ad_id has no description in the schema and the description doesn't clarify its format or requirements beyond being required. With 50% schema coverage, the description partially compensates but could go further.

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 begins with a specific verb and resource ('Delete an ad'), clearly distinguishing it from sibling tools like delete_ad_group or delete_campaign. It also states the scope and the permanent nature, removing ambiguity.

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 clearly ties usage to the active Space, explicitly telling the user how to switch (set_active_space) or override per-call (space_id). This is helpful context, though it doesn't explicitly mention when not to use the tool.

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