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

The description reinforces and expands on annotations: it states 'Every call is read-only and idempotent' (matching readOnlyHint and idempotentHint) and adds critical detail about error behavior—'never raises a protocol error—it returns {"error": ...}'. This plus the 'PREMIUM (license)' notice provides important context beyond annotations alone.

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 around 150 words and front-loads the core purpose, then flows through usage, example, error handling, and safety note. Every sentence serves a purpose, though minor tightening (e.g., removing the repeated 'PREMIUM' mention) could improve conciseness.

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 tool has 4 parameters (2 required), an output schema, and no nested objects, the description covers all aspects: what it does, when to use it, input format via example, output shape, error responses, and safety guarantees. It is sufficient for an agent to correctly select and invoke the tool without additional context.

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 coverage is 100% with detailed parameter descriptions. The description adds a concrete JSON example that illustrates the structure of the 'tasks' array and the response format, which aids comprehension beyond the schema's textual descriptions. While not transformative, the example is a meaningful addition.

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 begins with a specific action and resource: 'Plan a task schedule backward from a hard deadline in business days.' It clearly distinguishes from sibling tools by explicitly stating it is not for forward counting (business_days) or response-time targets (sla_due). This leaves no ambiguity about the tool's core function.

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 'when to use' ('Use when the end date is fixed and steps must be placed backward from it') and 'when not to use' with references to specific alternative tools. This gives the agent clear decision boundaries.

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