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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the useful detail of which fields are returned, which matters because there is no output schema, but says nothing about pagination, result limits, or the open-world account scoping it performs.

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 short sentences with the resource description first and the actionable routing second; the '(ad sets)' gloss and the field list earn their place. Minor deduction because the leading noun fragment lacks a verb, forcing a small inference about the operation type.

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 read-only, zero-required-parameter listing tool with full schema coverage, the description covers what is returned, how to narrow results, and why an agent would call it. Only return-volume behavior (pagination/limits) is left unaddressed, which is a modest gap for an open-world account listing.

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 100%, so all four parameters are already documented, which sets the baseline at 3. The description's 'Filter by campaign' echoes the campaign parameter but adds no format or matching semantics (name vs ID resolution) beyond what the schema already states.

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?

Names the specific resource (ad squads/ad sets) and enumerates the settings returned — status, campaign, optimisation goal, budget, bid, targeting, schedule — which cleanly separates it from snapchat_campaigns and snapchat_ads. The only weakness is that the opening is a noun fragment, so the agent must infer this is a read/list operation rather than being told with an explicit verb.

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?

Gives real when-to-use guidance: 'Use to find IDs and settings before changes or duplicating', which frames it as a discovery step preceding mutation tools like snapchat_update_budget or snapchat_duplicate. It doesn't name the sibling alternatives (e.g. snapchat_campaigns, snapchat_ads, snapchat_performance) explicitly, so the exclusion side is only implied.

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