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

Annotations only supply destructiveHint=true, and the description adds real semantic context: the block consumes availability so it cannot be booked. It does not state permission requirements, what happens to any existing appointment in that window, or whether the block can later be removed or edited. The 'prevents booking' framing and the destructive hint are broadly consistent rather than contradictory.

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?

Three tight sentences, front-loaded with the operation and its effect; the 'One-off only' constraint and the GraphQL mapping name both earn their place.

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 6-parameter mutation with no output schema, the description covers what is created, its effect, and its one-off limitation. It omits return information (the created timeblock identifier) and failure/permission context, which is a minor gap rather than a blocker.

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 (title, reason enum, duration bounds, staff_id, start_time, location_id) is already documented in the schema. The description only loosely maps to staff/location and adds no format or constraint detail beyond it, so the baseline of 3 applies.

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+resource+scope: blocking time on one staff member's calendar at a location, and clarifies the effect ('so it cannot be booked'). This is clearly distinguishable from read-side siblings like boulevard_list_timeblocks.

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?

'One-off only' constrains the use case (no recurring blocks) and the parenthetical names example reasons (break, meeting, personal time), implying intent. However, it never names alternatives or when-not-to-use cases, e.g. how to view existing blocks or how this differs from shift management.

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