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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), so the description only needs to add context. It usefully supplies the IANA format convention for timezone, but says nothing about partial-update semantics or whether omitted fields are preserved — notable for a mutation tool with zero required parameters.

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 dense sentence with no filler; the most identity-defining setting (time zone) is front-loaded and the parenthetical IANA example is embedded where it is needed. Nothing is restated from the schema or 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?

A five-parameter mutation tool with 0% schema coverage and all-optional parameters needs to clarify partial-update behavior and the display_name field, neither of which is addressed. What is covered, the four documented settings, is covered well, and the absence of an output schema means return values need no explanation.

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%, so the description carries the full burden. It competently translates four of five parameters into plain language (timezone with an IANA example, slot_step_minutes as start-time frequency, min_notice_minutes, booking_window_days), leaving only display_name unexplained.

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 (Change) and resource (calendar settings) and enumerates the four setting families it governs: time zone, start-time slot frequency, minimum client notice, and booking horizon. It is distinguishable from set_calendar_hours or save_calendar_service, though it does not explicitly name the boundary against those siblings.

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?

No explicit when-to-use or when-not-to-use guidance, and no alternative tool is named despite numerous adjacent siblings (set_calendar_hours, save_calendar_service, remove_calendar_service). Usage must be inferred from the setting names alone.

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