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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is fully covered. The description adds essentially nothing beyond that: it doesn't say whether returned slots are filtered by calendar, what a slot looks like, or that a 2-week max range applies (that lives only in the schema).

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 short sentence with no wasted words, and the key action is front-loaded. It is arguably under-specified rather than over-long, so brevity here is a mild virtue, not a flaw.

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, well-annotated read tool with a fully documented 3-parameter schema and no output schema, the description is adequate but thin. It leaves the agent to infer the returned slot structure and the booking workflow context from sibling names rather than stating it.

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%, with date-time formats, the timezone default, and the 'max range is 2 weeks' constraint all documented in the schema itself. The description adds no parameter meaning on top, which is the correct baseline of 3 when the schema carries all the weight.

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: 'Retrieve available appointment slots from the calendar'. It is clear what the tool does, though it does not differentiate itself from siblings like book_appointment, reschedule_appointment, or cancel_appointment, which any agent would need to choose among.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no mention of alternatives such as book_appointment. The usage is only implied: an agent infers this is a pre-booking availability lookup, but nowhere does the description state that.

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