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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds meaningful behavior beyond that: the route is not saved, the tool is anonymous, the day count is honored exactly or explained, and the user should be sent to a questionnaire URL to persist or adjust the route. No contradiction with annotations.

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?

Three sentences with no waste. The core promise and key constraints are front-loaded, and every sentence contributes operational guidance: what the tool produces, the fidelity guarantee, prerequisite tool usage, and non-persistence.

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?

The description covers essential call context: valid id source, itinerary guarantees, and persistence semantics. However, with 10 parameters, no output schema, and several required free-text fields not explained, the agent is left uncertain about exact expected values for who, style, and vibes, as well as the precise return shape beyond the questionnaire URL.

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?

The schema already describes pace, cities, kosher, duration, arrivalDate, and shabbatCity, covering 60% of parameters. The description adds useful semantics for cities ('Every city you list appears in the route') and duration ('the number of days you ask for is honoured exactly'). However, required fields like who, style, and vibes remain unexplained in both the schema and the description, leaving meaningful gaps.

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 title and description clearly identify a route-building tool: 'Build a day-by-day Morocco route' and 'free, anonymous, day-by-day itinerary.' It is easily distinguished from the sibling lookup/search tools, which fetch city guides, options, shabbat times, visas, or site information rather than generating a personalized itinerary.

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 gives a concrete prerequisite: 'Use get_plan_options first for valid ids,' which tells the agent what must happen before calling this tool. It does not explicitly enumerate exclusions or alternative tools, but the planning-vs-lookup distinction among siblings makes the usage context reasonably clear.

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