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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds nothing behavioral beyond that — no data freshness, no indication of what 'live' means temporally, no result-size or coverage caveats for an open-world aggregator.

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 front-loaded sentence that leads with the resource ('Cross-channel ads picture') before enumerating contents. The comma-separated list is dense but each item carries distinct informational value; no filler sentences.

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 no output schema, the description usefully enumerates what the result contains (channel mix, gaps, insights with actions), which compensates for the missing return specification. Annotations cover the safety profile and the lone parameter is fully documented, leaving only guidance on alternatives as a gap.

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 coverage is 100% and the single optional 'domains' parameter is fully documented in the schema (format, maxItems, omission behavior). The description mentions 'your brand vs rivals' but adds no syntax or selection guidance beyond the schema, 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?

The description names the specific resource and its scope — 'cross-channel ads picture (Meta, Google and others) for your brand vs rivals' — and enumerates the dimensions returned (live/new ads, channel mix, coordinated pushes, gaps, prioritized insights). It is clearly differentiable from siblings like get_social_media_channels_and_followers or get_competitor_moves_feed, though it uses no verb and reads as a noun phrase rather than a stated action.

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 statement of when to reach for this tool versus the many adjacent siblings (e.g. get_full_brand_snapshot or get_competitor_moves_feed), and no prerequisites, exclusions, or trigger conditions are given. The agent must infer usage purely from the topical scope.

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