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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world. The description adds real value beyond that: it applies daylight saving changes, works in a fixed 09:00–17:00 window, and disclaims calendar access or invitation sending. The main omission is behavior when no valid slot exists.

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?

Two tight sentences with zero filler; the constraints come first and the negative boundaries follow. Every clause earns its place.

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?

With an output schema present, return-value explanation isn't required, and the description covers inputs, constraints, and boundaries well. The only gap is what an agent should expect when no 30-minute slot satisfies the window.

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 50% (date and zone documented, name not), but the description adds the crucial semantic that the date is interpreted in the first person's time zone, which the schema does not state. The 2–8 constraint is also reinforced, adding meaning beyond a bare schema read.

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 (Find), resource (30-minute meeting times), and hard constraints (09:00–17:00, 2–8 people, IANA zones). An agent can distinguish this from cron_next_runs or recurring_schedule purely from the description.

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?

Explicitly scopes what it is not: 'does not read calendars or send invitations', which tells the agent this is a pure computation, not a scheduling action. It also clarifies the date is local to the first person. It stops short of naming alternatives for scheduling-adjacent tasks, so it's clear context without full alternate routing.

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