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

The description goes well beyond the annotations: it discloses that deletion stops syncing, removes the ad from the list, hard-deletes the ad's feeds/channel profiles, and has no restore tool. It also explains the HTTP 400 error when confirm is missing and specifies the exact return payload. This is unusually transparent for a destructive 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?

The description is dense but every clause earns its place. It front-loads the destructive warning, then covers confirmation behavior, scope of deletion, return value, and parameter provenance in a tight sequence. No filler or repetition.

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 destructive, multi-effect mutation with a confirmation guard, the description covers the essential context: what is deleted, what is not affected (no order sync), what happens without confirmation, how to get required IDs, and the expected return. There is no output schema, so the return shape description is necessary and sufficient.

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 must carry parameter meaning. It does: ad_id is sourced from list_ads, confirm must be true to execute, and project_id is optional/inferred unless project_id_required, in which case list_projects is the prerequisite. This fully compensates for the bare schema.

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 states a precise verb and resource ('Delete an ad') and immediately differentiates ads from marketplaces: 'Ads are ads-based channels ... not marketplaces: they publish products to the ad platform and have no order sync.' This clearly distinguishes it from sibling tools like delete_marketplace and delete_feed.

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?

Usage guidance is explicit and actionable: confirm with the user first, call with confirm:true, warn that deletion cannot be undone. It also gives the failure mode ('Without confirm:true the call returns error confirm_required') and instructs when to call list_projects for project_id. No inference is left to the agent.

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