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 value by disclosing the return payload (review status including rejection reason, creative ID linkage), but says nothing about pagination, cross-account scope, or volume, which matters for an openWorldHint 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?

Two tight sentences with no filler, and the returned-field list is front-loaded before the filter sentence. It is telegraphic enough that the missing verb costs a bit of clarity, but nothing 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 annotations and no output schema, the field enumeration usefully substitutes for return-value documentation. However, it omits scope (all ads in account vs. filtered), pagination limits, and how an agent should choose between this and snapchat_adsquads or snapchat_creatives.

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 80%, so the schema already documents folder, account, adsquad, and language. The description only clarifies that campaign and adsquad act as filters, which marginally compensates for the undocumented campaign parameter; 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?

The description enumerates the fields returned (status, review status with reason, ad type, creative ID, ad squad), which implies a read/list tool, but it never states a verb or object explicitly ('Retrieve Snapchat ads'). Mentioning creative ID and ad squad does help distinguish it from snapchat_creatives and snapchat_adsquads, but the differentiation is incidental rather than stated.

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?

'Filter by campaign or ad squad' gives a scoping hint, but there is no when-to-use guidance, no mention of alternatives such as snapchat_adsquads or snapchat_performance, and no note on prerequisites like needing an account context or the single-account default.

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