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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld). The description adds genuinely useful context beyond them: the plan is weather- and open-status-aware, diet filtering names real OpenStreetMap places, and each meal reports diet/diet_note. It does not describe the response structure in detail, but for a read tool with annotations this is solid added value.

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?

The opening 'Spin My Day. Build a day out.' merely restates the name and title, and the trailing 'in a city, near a location, or in a random city' repeats the random-city instruction already given one sentence earlier. The middle sentence carries real information, but roughly a third of the text is redundant.

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 an 8-parameter, all-optional, read-only tool with no output schema, the description conveys the intent, the random-city fallback, weather/open awareness, and diet behavior. Nothing critical is missing, though a hint about the returned itinerary shape (beyond diet_note and tomorrow) would round it out.

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 100%, so the schema already documents lat/lon, city, date, diet, seed, vibe and budget. The description restates the city-omission and diet semantics without adding format or edge-case detail the schema lacks (e.g., how diet lists are parsed, how seed interacts with idempotentHint). Baseline 3 is appropriate.

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 outcome (spin up a full day out with named time blocks: morning, lunch, afternoon, dinner, evening) and scopes it by weather and opening status. An agent can tell what it produces. It does not explicitly differentiate from the only sibling, spinmyday_list_vibes, but the resource is distinct enough not to confuse them.

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?

'Leave out city and location to spin for a random city' gives one clear conditional for the random-mode path, and the schema reinforces it. There is no guidance on when to prefer this over list_vibes (e.g., to discover valid vibes first), so usage is only partially covered.

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