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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds real domain context such as configured vs effective status and whether budget lives on the campaign (CBO) or ad set (ABO). It does not address result size, pagination, or whether large accounts are truncated, which is the main remaining behavioral unknown for a 'returns every campaign' read.

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?

Front-loaded with the verb and resource, then the field inventory, then the usage sentence — good ordering. The field enumeration is long but most items (CBO/ABO, learning stage, hook) carry genuine selection value rather than 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?

For a simple, parameter-light read tool with no output schema, the description does the heavy lifting of describing the return payload and a concrete use case. It leaves account scoping and result-size behavior unstated, a minor gap given the tool's simplicity.

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 single parameter is fully documented in the schema ('Include paused campaigns. Default true.'), so the baseline of 3 applies. The description's 'Returns every campaign' does not clarify that paused entities can be excluded or that this is toggleable, adding nothing beyond the schema.

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 ('Returns every campaign, its ad sets and its ads') and enumerates the exact fields returned, including CBO/ABO budget placement and configured vs effective status. That inventory clearly separates it from siblings like get_ad_insights and get_performance_report, which report metrics rather than structure.

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?

'Use it to find entity ids before drafting a change and to check where a budget lives' gives a concrete, actionable context with an implied workflow (read structure, then mutate). It does not name an alternative or state when not to use it, so it stops short of a full when/when-not pairing.

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