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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description's deletion semantics are partly redundant; however it adds genuinely new operational context — the required SULVO_API_KEY with inventory:write scope and server-side ownership enforcement. It does not explicitly say the deletion is irreversible, which would have earned a 5.

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?

Three compact sentences, front-loaded with the action and scope, then the auth requirement. No filler or repetition of the title.

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 single-parameter deletion tool with annotations covering the safety profile and no output schema, the description covers action, ownership semantics, and credential/scope requirements. Nothing an agent needs to invoke it correctly is missing.

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 100% and the single adId parameter is fully documented in the schema, so the description's 'by id' adds nothing beyond it. Baseline 3 applies when the schema carries the parameter burden.

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 names a specific verb and resource ('Delete a Sulvo ad unit by id') and adds a scoping constraint ('for an approved publisher'). This clearly distinguishes it from the sibling create_sulvo_ad_unit and the unrelated delete_sulvo_advanced_report without needing either schema.

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?

It states the conditions for use: the publisher must be approved and the API key's account must own the unit. There is no explicit 'when not to use' or named alternative, but the preconditions are concrete enough that an agent knows when invocation will fail.

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