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

Annotations declare readOnlyHint=false and destructiveHint=false, so the agent knows this mutates state but is not framed as destructive. The description adds real value by naming the observable consequence (events stop blocking bookings), which implies double-booking risk, but it is silent on reversibility (re-run select_calendar?), permission/credential requirements, and whether existing bookings are affected. No contradiction with annotations.

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 tight sentence with the effect front-loaded after the action. Nothing to trim and nothing buried.

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 4-parameter state-mutating tool with no output schema, the description covers what changes but not what an agent needs to call it safely: the inverse operation for rollback, the undefined delegationCredentialId, and any credential scoping for credentialId. Annotations give the safety profile, so this is adequate rather than complete.

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 75% and the description offers no parameter detail at all — all semantics come from the schema. Three of four params are documented there via 'from list_calendars'; only delegationCredentialId is undocumented in both places. Baseline 3 applies since the schema carries nearly 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 ('Exclude a connected calendar') plus the concrete effect ('from busy-time checks'), which is far more than a restatement of the name. It doesn't explicitly contrast with the inverse sibling select_calendar or with disconnect_calendar, but the phrasing 'events stop blocking bookings' implicitly separates it from removing a connection entirely.

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 condition for use is implied by 'its events stop blocking bookings' — you would call it when a calendar should no longer affect availability. There is no explicit when-not guidance (e.g., use disconnect_calendar to remove the connection instead, use select_calendar to reverse), and no prerequisites are stated.

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