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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: determinism via seed and the returned spin_again link, the post-5pm date rollover signaled by a 'tomorrow: true' flag, and the diet filtering that names real OpenStreetMap-listed venues. Return structure is only gestured at, which keeps it short of a 5.

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 payload sentence is front-loaded and dense with actionable detail, but the opening 'Spin My Day. Build a day out.' merely echoes the tool name and title, spending a sentence on what the name already conveys. The remainder is efficient.

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, no-output-schema generator, the description covers the essentials: what gets produced, how weather/opening hours constrain it, and how omitted inputs default. It stops short of explaining result shape or failure modes (e.g. no city found), which is the only notable gap.

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 every parameter (lat/lon, city, date, diet, seed, vibe, budget) is already documented with its own semantics and enum values. The description largely restates the omitted-argument behaviors rather than adding new meaning, so the 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?

The description states a concrete verb and resource — it builds a full day out spanning morning, lunch, afternoon, dinner and evening, constrained by weather and opening hours, in a city, near a location, or a random city. This is specific enough to distinguish it from its only same-namespace sibling, spinmyday_list_vibes, without opening either schema.

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?

It gives useful default-routing guidance ('leave out city and location to spin for a random city', omitted date defaults to today or tomorrow after 5pm), which tells the agent how to call it. However, it never states when to reach for this tool versus alternatives, and it does not name or reference the sibling spinmyday_list_vibes that an agent would likely need first to pick a vibe.

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