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

Annotations only declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, which are not very informative. The description compensates by disclosing important behaviors: 'Uses this month's generation allowance,' 'hook burns Current karaoke,' and 'hookTemplateId ... does not change consume or refund.' It also explains the captionMode nuances. No contradictions found.

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 dense but highly efficient, packing critical facts into a few sentences. It front-loads the main action and immediate follow-up (poll), then clarifies key parameters without redundancy. Every sentence adds new information, and the structure is streamlined.

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?

Given the complexity (17 parameters, nested objects, enums) and the presence of an output schema, the description provides sufficient context for correct invocation. It covers the most complex behavioral aspects (captionMode, hookTemplateId, idempotency) and directs the agent to the right polling tool. The output schema handles return values, so nothing critical is missing.

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?

With 100% schema description coverage, the schema already documents each parameter well. However, the description adds extra context for specific parameters like hookTemplateId ('seeds the brief from Opening hooks, script opening, not caption style') and captionMode details about operator-email limitation. This goes beyond the schema, justifying a score above baseline 3.

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 action: 'Start a paid Talking Short.' It specifies the resource (a paid Talking Short generation) and differentiates it from siblings like generate_topic_short, generate_ad, and the other generate_* tools. It also mentions key constraints like using the monthly allowance and polling get_talking_short for completion.

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 provides explicit guidance on when and how to use the tool: 'Poll get_talking_short until it finishes.' It also explains conditional behavior like captionMode defaults and the operator-email restriction for the Phrase chip. This is clear enough for an agent to know exactly what to do.

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