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

The description goes beyond the raw annotations: it explains the merge behavior (sending one channel cannot switch the other off), the global silencing semantics of setting a channel to false, and the interaction with alert rules. This is valuable behavioral context that the annotations alone (readOnlyHint=false, destructiveHint=false) do not convey.

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?

The description is well-organized into three concise paragraphs: what the tool does, the behavioral consequence, and the exclusion for Slack/Discord. Every sentence carries meaningful information, and the most important behavior (merge) is front-loaded.

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-parameter update tool with a rich output schema and complete schema coverage, the description fully covers what an agent needs: scope, merge behavior, silence semantics, exclusions, and the relationship to alert rules. Nothing is missing for correct invocation.

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?

The schema already has 100% coverage and a rich description of the channels parameter. The tool description reinforces the key semantics (merge, not replace) and the delivery model, but the schema itself is already strong, so the description adds moderate extra value.

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 clearly states it updates a person's personal channel preferences (in-app and email) with a specific merge behavior, distinguishing it from account-level connections. It names the sibling get_channels and the broader family of update_* tools implicitly by being explicit about what it does.

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 description explicitly explains when to use this tool (updating a person's channel preferences) and when not to (Slack/Discord are account-level, admin-only, dashboard). It also explains the relationship to alert rules, giving clear context for when this tool is the right half of the delivery mechanism.

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