Business-hours deadline / SLA

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the description correctly focuses elsewhere. It adds genuinely useful operational context the annotations cannot carry: DST-awareness, custom hours/workdays, holiday handling, and the pricing model (25 free calls/day, then $0.001 via x402). Only the return shape is unaddressed, which the output schema covers.

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?

Four short sentences: capability, use cases, feature coverage, pricing. The key capability is front-loaded and no sentence is padding for a tool of this scope.

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 10-parameter scheduling calculator with an output schema and read-only annotations, the description covers the essential decision points: which mode to use, what it handles (DST, custom hours, holidays) and what it costs. The remaining gap is guidance on how the holiday-related parameters combine.

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 roughly 50%, and the description does clarify the mode-selection logic (hours/minutes yields a deadline; end yields an elapsed count), which is the most important semantic choice. But it says nothing about work_start/work_end, workdays, holidays, or how country interacts with the holidays array, leaving several parameters to the schema alone.

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-and-resource framing ('SLA math in working hours') and enumerates the two distinct operations: computing a deadline N business hours after a start, or counting business time between two times. It implicitly separates itself from plain date_add/date_diff by emphasizing business-hours semantics, though it never names a sibling tool.

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?

It gives concrete use cases ('support-ticket SLAs, response-time targets and office-hours deadlines') that let an agent recognize the right context. It lacks an explicit when-not clause or a named alternative such as working_hours_overlap or date_add, so a 4 rather than a 5.

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