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

Annotations already declare this as a non-idempotent, non-destructive mutation in an open-world system, so the safety profile is covered. The description adds no behavioral context beyond that: it says nothing about the `confirm` gate, what happens to duplicate/existing keywords, whether changes are reversible, or error behavior. The match-type advice is strategic domain knowledge, not behavioral disclosure.

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?

Two sentences with the core action front-loaded and no filler. The second sentence is somewhat rambling, but every clause carries advice rather than repetition of structured fields.

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 write tool with annotations covering the safety profile and no output schema, the description is adequate on intent and match strategy. It falls short by omitting any mention of the `confirm` parameter and the identifiers required, which an agent needs to invoke it 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?

Schema description coverage is 0%, so the description must carry the parameter burden. It partially explains the `match` enum by recommending PHRASE/EXACT over BROAD, but leaves customer_id, ad_group_id, the keywords array shape, and critically the `confirm` boolean entirely unexplained — a significant gap given the mutation nature of the tool.

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 ("Add keywords to an ad group"), which is immediately distinguishable from the sibling ads_add_negative_keywords and from the discovery tool ads_keyword_ideas. It does not explicitly name those siblings, but the action is unambiguous.

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 second sentence gives genuine decision guidance on match type ("Prefer PHRASE or EXACT for a local business"), which is implied usage context. However it never states when to choose this tool over alternatives like ads_keyword_ideas (for discovery) or ads_add_negative_keywords, so routing guidance is incomplete.

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