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

Annotations already declare readOnlyHint/idempotentHint, so the 'Read-only' closing note is confirmatory rather than additive. The description does add real behavioral detail beyond annotations: stable item keys, a plan revision, per-item flags (editable, canRemoveForDay, canMark), and the note that course doses and meals can be marked done.

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?

A single dense sentence carries the return contents and flags up front, followed by a short capability note and a two-word safety tag. Efficient and front-loaded, though the flag list is packed tightly enough to read as a run-on.

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 no output schema, the description carries the return-shape burden and does so adequately: it names the item categories, the keys/revision, and the per-item flags. Missing only minor details such as behavior on an empty date or error handling.

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?

There is only one parameter and the schema gives no description, but the description supplies the expected YYYY-MM-DD format and the 'one date' semantics, compensating for the 0% schema description coverage. It adds the essential meaning the schema alone lacks.

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 opens with a specific verb and enumerates the exact resources returned (tasks, events, course steps, meals) scoped to one date, which clearly separates it from narrower siblings like zarok_get_meals or zarok_get_courses. An agent can distinguish the tool's scope without opening the 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?

Usage is implied by the scope ('for one date'), but the description never states when to prefer this over zarok_get_meals, zarok_get_courses, or zarok_get_week_summary. No explicit exclusions or alternative routing are given.

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