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

Annotations already carry readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds useful output context (that all exceptions are included, and the workDays 0..6 Sunday=0 encoding), but says nothing about error behavior for a bad calendarId or pagination.

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 tight sentences with no filler, and the completeness framing is front-loaded ahead of the encoding detail. Every sentence earns its place, though the workDays note could be seen as slightly tangential to selection.

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 single-param idempotent read with no output schema, the description supplies the missing return-shape information (exceptions plus the workDays encoding) and safety is covered by annotations. Nothing critical for correct invocation is absent.

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 0% and the sole parameter calendarId is never described in the description; the mention of workDays refers to an output field, not the input. The description therefore does not compensate for the coverage gap, though the param name is fairly self-evident.

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 ('Full working-calendar detail') and clarifies scope as 'every exception (holidays, special working days).' It's clear what the tool returns, though it never names the sibling list_working_calendars to differentiate the detail fetch from the list operation.

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?

Usage is only implied: the phrase 'Full ... detail' suggests this is the choice when the complete exception set is needed, versus the listed calendars. There is no explicit when-to-use, when-not, or reference to the list sibling, leaving routing largely to inference.

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