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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds real value beyond that by disclosing the payload contents: fields, limits, pricing models, minimum bids, minimum order, image rules and a sample order with price — important since no output schema exists.

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 opens with "The catalog:" and then lists return contents in one compact sweep; the closing imperative adds the action. No redundant framing or filler.

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?

With no input parameters and no output schema, the only real risk is the agent not knowing what comes back or when to call it. The description covers both the returned data shape (fields, limits, pricing, minimums, image rules, example order) and the workflow trigger.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies a full-catalog, no-filter read rather than suggesting unsupported selection arguments.

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 catalog: every ad format (PTC, Sponsored Listing, Banner, Native, Paid Visits)" gives a concrete resource with an explicit enumeration of format types, which separates it from list_ads (actual ad instances) in the sibling list. What's missing is only an explicit contrast sentence naming that sibling, so it stops just short of a 5.

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?

"Read this before building an order" is a direct, actionable usage instruction that positions the tool as a prerequisite to create_ad/quote_ad. There is no when-not guidance (e.g. skip this if you already know the format ID), so it is clear context without exclusions.

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