storyline_estimate

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

With no annotations provided, the description fully discloses safety-relevant behavior: it is 'Read-only dry-run' and does not actually run the storyline. It also reveals the return format ({ estimatedCredits, lineItemBreakdown }), adding concrete behavioral context beyond the schema.

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 long, front-loaded with the critical safety qualifier 'Read-only dry-run.' Every sentence adds value: purpose, usage guidance, and return format. No redundancy or fluff.

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?

Despite lacking an output schema, the description provides the expected return shape. It covers what the tool does, when to use it, and that it has no side effects. For a simple two-parameter estimate tool, this is fully complete.

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?

The input schema already provides 100% coverage for both parameters (brandId and storylineId), so the description adds no additional parameter-level meaning. Baseline of 3 is appropriate because the schema does the heavy lifting.

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 uses a specific verb 'estimate' and clearly identifies the resource ('credits required to execute the storyline'). It distinguishes the tool from siblings by explicitly stating it does NOT run the storyline ('without actually running it'), contrasting with storyline_execute. This makes the purpose unambiguous.

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 explicitly says to use this tool before storyline_execute to surface costs for user approval. This names the intended workflow, the alternative tool, and the context of use. It implicitly warns against using it when actual execution is desired.

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