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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known. The description adds genuinely useful nuance beyond that: data is retained by default, irreversible deletion happens only with delete_data: true, and reconnection requires the user to sign in again. That is solid added context, though there's no mention of whether in-flight syncs are cancelled or what happens on partial failure.

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?

Front-loaded with the action and its effects, followed by the destructive variant, the confirmation warning, and the recovery path. Each sentence carries information; the only mild redundancy is repeating the delete_data behavior already present in the schema.

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 two-parameter destructive mutation with no output schema, the description covers the required confirmation, default-retention behavior, the permanent-deletion branch, and the reconnection story. Nothing an agent needs to call this safely is missing.

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 100%, so both parameters are already documented in the input schema, including the delete_data default. The description restates the delete_data consequence in slightly stronger terms ('deletes all of the source's data permanently') but adds no provider-slug format or validation guidance beyond what the schema says. 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 description opens with a specific verb and resource ('Disconnect a data source') and immediately distinguishes itself from connect_source by naming the inverse operation. It also spells out the two-part effect (stops syncing, removes connection) so the agent knows exactly what the operation means.

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 a clear when-to-use cue plus a confirmation requirement ('Confirm with the user before calling') and a reversal path ('To connect the source again, the user signs in to it again'), which implicitly points at connect_source. It stops short of explicitly naming connect_source or stating when not to disconnect (e.g., mid-sync).

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