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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds which fields are returned, which is modest value, but says nothing about pagination, result volume, or how the listing is scoped when folder/account are omitted.

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 well-formed sentence with the resource and the returned fields front-loaded, and no filler. It is perhaps too terse for the sibling landscape, but nothing in it is wasted.

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 listing tool with fully documented optional parameters and no output schema, the definition is minimally sufficient. It omits any statement of scope or filtering behavior, which an agent would need to call it confidently in a multi-account setup.

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 three parameters (folder, account, language) are already documented, and the enum on language is explicit. The description adds no extra meaning about how those filters affect the listing, so the baseline 3 applies.

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 plus resource ('List Snapchat campaigns') with the notable fields it surfaces (status, objective, daily budget). An agent can tell it is a read/list operation on Snapchat campaigns, but the description never contrasts it with siblings like snapchat_create_campaign, snapchat_launch_campaign, or the parallel meta_campaigns/tiktok_campaigns tools.

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?

There is no when-to-use guidance at all: nothing says whether this is for overview vs. performance analysis (snapchat_performance), whether it needs a folder or account selected first, or what to do when multiple accounts are enabled. The only implied usage comes from the tool name itself.

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