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

readOnlyHint=true already establishes this as a safe read, and the description adds a useful scope distinction between public/system prompts and workspace prompts. Beyond that it discloses nothing further (no pagination, no behavior when prompt_id is missing for prompt_details). With annotations carrying the safety profile and an output schema present, a 3 is appropriate.

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?

One framing sentence followed by a compact numbered list of the two modes. Every line earns its place and the purpose is front-loaded before the parameter routing.

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 an output schema present, return values need not be explained, and the description covers both request modes and the parameters each requires. Minor residual gaps are the prompt_type value space and error behavior for a missing prompt_id, but an agent has enough 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 load — and it does: it names request, prompt_id, is_custom, prompt_type, and workspace_id and explains which mode each belongs to. It falls short of the top mark because it doesn't state the accepted values for prompt_type or what is_custom defaults to.

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: 'Browse the Microsoft Ads prompt catalog.' The two numbered request modes clarify the distinct operations (listing vs. fetching a prompt body), which lets an agent separate this from the sibling query/execute tools. It stops just short of explicitly contrasting with those siblings.

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 description gives clear per-mode routing: 'request=menu' for listing, 'request=prompt_details' for fetching by id, plus the condition for workspace prompts (is_custom=True + workspace_id). It does not say when to choose this tool over query_contexts or query_data, but for a two-mode catalog tool the internal routing is explicit.

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