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

Beyond the annotations (destructive, idempotent, not read-only), the description discloses the permission needed, the fact that the first call is a no-op validation pass, that it rejects unknown fields by name, and that it returns a summary plus a confirm_token. That is exactly the extra context an agent needs before performing a destructive mutation.

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?

Four short sentences, front-loaded with the action, then the permission, then the flow. Wording like "checks the arguments as the change would" is slightly convoluted but still parses correctly and nothing is redundant.

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 destructive two-parameter tool with no output schema, the description covers auth, the confirmation protocol, validation behaviour, and what each call returns. It could say more about consequences for existing bookings or recurring occurrences, but the essential calling information is present.

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 coverage is 50%: confirm_token is already documented in the schema, and id is self-evident, so the description mainly reinforces the existing meaning ("same arguments plus confirm_token"). It adds a little on validation behaviour but no new detail about id format or what a summary contains; baseline 3 is appropriate.

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?

The first sentence names a specific verb and resource (remove a busy block) that matches the title, so the operation is immediately identifiable. Among siblings such as create_busy_block, update_busy_block and restore_busy_block the intended action is distinguishable by name, but the description never explicitly contrasts itself with those near-neighbours (e.g. restore_busy_block or skip_busy_occurrence).

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?

It gives clear operational guidance: requires the calendar:write scope and must be driven as a two-call flow, with the second call made only after the person agrees to the summary. What is missing is guidance on when to prefer this over restore_busy_block/skip_busy_occurrence for adjacent calendar-block scenarios.

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