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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds no behavioral context of its own – no indication of how activities are ordered or split, whether empty days are allowed, or what the result looks like.

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?

It is short with no filler, but that brevity comes from under-specification rather than discipline – there is essentially one phrase and no front-loaded statement of the operation, inputs, or output.

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?

A tool with three parameters, two of them required, an undocumented array input, and no output schema needs the description to explain the core transformation. Three words say nothing about what an agent needs in order to call it correctly.

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 description coverage is only 33%: 'days' and 'activities' have no descriptions at all, and only 'startDate' is documented. The description does not compensate by explaining whether days is a count, whether activities are evenly distributed, or how many activities are allowed.

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 three-word description 'Travel itinerary splitter' restates the tool name in different words and never states the actual operation: distributing a list of activities across a number of days. An agent cannot tell from this what the tool produces or how 'days' relates to 'activities'.

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?

No when-to-use guidance, no conditions, no alternatives are named. With siblings such as planning_travel_countdown and planning_packing_list nearby, the agent gets no signal about which of these trip-planning tools to pick.

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