Working-hours overlap

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

Annotations already establish readOnly/idempotent/closed-world, so the description needn't restate safety. It adds genuinely useful behavior beyond them: weekend-skipping default, a 14-day search bound, and a pricing/quota model (25 free calls/day, then $0.001 via x402) that an agent should know before repeat calls. Return shape is covered by the output 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?

Front-loaded with the core purpose in the first clause, followed by constraints and cost in compact clauses with no filler. Three dense sentences, though the pricing detail could be trimmed for a simple lookup call.

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 parameterized lookup tool with an output schema and helpful annotations, the definition supplies what an agent needs: purpose, scope bounds, defaults for the common flags, and operating cost. Remaining parameter details live in the schema where they belong.

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?

At 43% schema coverage, the description partially compensates: it conveys that participants may carry their own hours and that weeks are skipped by default. However, it never explains the two mutually exclusive input modes (timezones vs. participants) at the description level, the work_start/work_end defaults, or the date anchor — leaving gaps the schema only partly fills.

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?

States a specific verb and resource — finding overlapping working hours across time zones — with a concrete use case (best meeting times for distributed teams). No sibling tool (business_day, timezone_convert, business_hours_deadline) does this, and the definition makes that distinct role obvious.

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?

Clear context for when to reach for it (meeting scheduling across distributed teams), plus practical constraints: per-participant hours optional, weekends skipped by default, max 14 days. It gives no explicit sibling comparison or exclusion rules (e.g., versus business_hours_deadline or timezone_convert), which keeps it short of a 5.

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