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

Annotations declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), and the description adds genuinely useful context beyond them: no portfolio-level budget cap and no extra authorization required. It omits the two-step preview/confirm_id write flow, which is only visible in the schema.

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?

A single front-loaded sentence with two tight parentheticals; nothing is wasted. It could be marginally cleaner but is well structured.

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 create tool with annotations covering the safety profile and no output schema, the description covers purpose, constraints, and auth. The only meaningful omission is the confirm_id two-step behavior, which the schema does document.

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 coverage is 67%, and the schema documents the notable confirm_id preview/confirm mechanism and account_id. The description adds no parameter-level meaning, so it neither compensates for the gap nor enhances what the schema provides — baseline 3.

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?

Specific verb+resource ('Create an Amazon Ads portfolio') with a clarifying parenthetical that defines what a portfolio is (a grouping of campaigns). This clearly separates it from ads_list_portfolios and the ads_create_sp_* tools, though it does not name a sibling explicitly.

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 is implied ('to group campaigns') rather than stated as when-to-use, and there are no exclusions or alternative paths given. The note about scope/authorization offers some context but does not route the agent between options.

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