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

Annotations already declare idempotent, non-destructive, closed-world; the description adds genuinely new behavioral rules: the new time must be at least 15 minutes out and within a year, and the operation is only valid pre-post in manual mode. It stops short of saying what happens on violation (error vs. clamp) or what the response contains.

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?

Two sentences, front-loaded with the core action and constraints, then the disambiguation. No filler or repetition of structured fields.

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 a simple two-parameter mutation with rich annotations and no output schema, the description covers scope, time-window constraints, mode gating, and the sibling alternative. Nothing an agent needs in order to decide to call it is missing.

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 coverage is only 50% (slot_id is undocumented), so the description must compensate; the "at least 15 minutes from now, within a year" window is real semantics for the `when` parameter beyond the schema's bare ISO 8601 note. The slot_id parameter still gets no explanation of how to obtain it.

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 verb and resource ("Moves a slot of the calendar") plus the exact target dimension (day and time). It explicitly distinguishes itself from the sibling move_publication, so an agent can route between them 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?

Gives explicit preconditions ("Manual mode only, before it's posted") and names the alternative tool plus the condition that selects it ("For videos the user scheduled themselves use move_publication"). This is the when/when-not/alternative pattern done fully.

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