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 clear. The description adds valuable behavioral context: the tool is interactive and will ask for more information if a parameter is omitted. It also scopes the domain to 'real Australian signage' with a specific list, setting expectations beyond what annotations provide.

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?

The description is two sentences with no fluff. The first sentence front-loads the primary purpose and domain. The second sentence provides actionable usage instructions. Every word earns its place.

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?

The description is sufficiently complete for a 2-parameter tool with no output schema. It explains what the tool does, the domain, and the interactive behavior. It does not explicitly describe the return format, but the mention of 'next question' implies the response type, and with no output schema, this level of detail is acceptable.

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% with examples for each parameter. The description adds meaning by explaining that the parameters are optional and defines the fallback behavior ('omit either to get the next question'). This goes beyond the schema alone by clarifying the conversational flow.

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 clearly states the tool's function: 'Recommend Vivid Ads signage for a goal + business type'. It uses a specific verb ('Recommend') and a resource ('signage'), and provides concrete examples of signage types. This distinguishes it from sibling tools like vivid_price or vivid_product.

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?

The description gives clear usage context: 'Call with goal and business; omit either to get the next question to ask the customer.' This tells the agent exactly how to invoke it. It does not explicitly name alternative tools, but the purpose is distinct enough that a sibling comparison is not strictly necessary.

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