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

With no annotations, the description carries the burden and covers return behavior ('opaque material references and direct video addresses'), validation ('Keyword length is 2-200 characters'), and the core behavioral trait that it is text matching, not vector search. It does not mention error cases or pagination behavior, but the schema covers limit/offset and the operation is clearly read-only by nature.

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?

Five short sentences, front-loaded with the core action and scope, then return info, constraint, and alternative. No filler; every sentence contributes a distinct piece of information even if the length constraint repeats the schema.

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 tool with no annotations and no output schema, the description gives the essential behavior, return type, constraint, and routing to the alternative. It could be slightly more specific about how opaque material references should be consumed, but it is otherwise complete enough for correct invocation.

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 the baseline is 3. The description adds semantic context for the keyword parameter (text matching, not vector search) and summarizes optional game/date filters, but it does not significantly elaborate on the remaining parameters beyond what the schema already documents.

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 and resource ('Search creative copy and labels by keyword') plus optional game/date scope. Explicitly distinguishes itself from search_materials_v2 and from visual-description vector search, so an agent can tell it apart from siblings.

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?

Provides an explicit alternative: 'Use search_materials_v2 with query for bilingual concept expansion.' Also sets a when-not boundary with 'This performs text matching, not arbitrary visual-description vector search,' so the agent knows not to use it for visual queries.

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