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

Annotations already cover readOnly/idempotent/openWorld=false, so the bar is lower; the description adds real behavior beyond them by disclosing the bounded result scope (only 20 most recent items) and the 'cached/confirmed' freshness semantics. It does not mention ranking, matching behavior, or result limits per category.

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 sentences, zero filler, scope stated first and the bounded/read-only caveat second. Every clause carries information an agent needs.

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 an output schema present, return values need not be explained, and the description adequately covers what is searched and its bounds. The only material gap is how the single required query is interpreted, which is left to inference.

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?

Only one parameter (query) with 0% schema description coverage, so the description could have said how the string is interpreted (keyword vs natural language, matching target). The enumeration of searchable content implies the query spans those three areas, which is minor added value, but nothing about length, syntax, or matching is explained.

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 (Search) and enumerates the exact resource set covered: confirmed brand context, the 20 most recent saved campaigns/AI plans, and cached Insights. This lets an agent distinguish it from siblings like campaignList, brandContextGet, and insightsPostList, though it never names those alternatives directly.

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?

It rules out two wrong uses (not an exhaustive archive, not a web search) which is genuine negative guidance, but it never states when to prefer this over campaignList/brandContextGet for specific lookups. Usage is implied rather than prescribed.

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