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

The readOnlyHint annotation already establishes this is a safe read, so the bar is lower. The description adds the upstream REST mapping (GET /blocks), which is useful context, but says nothing about pagination, default/maximum result behavior, or whether a date range is needed for meaningful results.

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, front-loaded with the resource and scope, with the API mapping appended as secondary detail. Nothing is wasted.

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 read-only list tool with fully documented parameters and no output schema, the description covers what is returned at a high level. The only real gap is that it does not help the agent choose between listing blocks and querying availability, which the surrounding sibling set makes relevant.

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 max, maxDate, minDate, and calendarID are all documented in the schema itself. The description adds no parameter meaning beyond that, which is the expected baseline when the schema carries the load.

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 ('List') and resource ('blocked-off (unavailable) time ranges on the account's calendars'), which is clearly distinct from sibling resources like appointments, clients, or calendars. It does not explicitly name or differentiate itself from the availability tools (acuity_availability_times/dates), but the resource is unambiguous enough for an agent to identify it.

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?

The description gives no when-to-use guidance, no conditions for selecting this over the availability tools, and no prerequisites. Usage is only implied by the resource name; an agent gets no routing help.

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