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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the mutation/safety profile is covered. The description adds real value by stating the partial-update contract and decoding is_active=false as 'pause', but it omits what happens to already-booked occurrences when a slot moves, and what 'moves' actually means against existing sessions.

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 compact sentences with zero preamble; the action set is front-loaded and the partial-update rule is the closing imperative. Nothing is padded or repeated from the title.

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 partial-update mutation with no output schema, the description covers the shape of the call but not the side effects an agent needs to reason about: impact on existing bookings when a slot moves, whether re-activating a paused slot restores lost occurrences, and permission requirements. Adequate to invoke, thin on consequences.

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 only 38%; slotId, start_time, and day_of_week are documented in the schema, but title, location, is_online, and duration_minutes carry no descriptions at all. The description compensates for exactly one field (is_active meaning pause) and adds nothing for the four undocumented ones, leaving the agent to guess semantics such as timezone or units.

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?

Clear specific verbs (moves, pauses, edits) paired with a concrete resource (a recurring weekly slot), and the parenthetical '(is_active false)' even names the mechanism for pausing. It does not distinguish itself from the very similar create_schedule_slot, schedule_class, reschedule_class, or update_class siblings, so an agent still has to infer the boundary.

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?

'Send only what changes' is genuinely useful partial-update guidance that implies this is a PATCH-style operation. However it says nothing about when to prefer this over reschedule_class or update_class, nor about any prerequisites such as ownership or whether the slot must be inactive before moving.

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