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

Annotations only give a coarse safety profile (not read-only, non-destructive, non-idempotent, not open-world). The description adds real behavioral context beyond them: the callback must be HTTPS, Corbah POSTs a JSON event to it, and a token is returned for later unsubscription. It does not describe delivery guarantees, retries, or failure handling.

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?

Three short sentences, front-loaded with the purpose, then the mechanics, then the return value. Every sentence adds information; none 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 single-parameter tool with no output schema, the description covers purpose, the callback contract, and the return value. It is nearly self-sufficient, missing only lifecycle details such as event frequency or whether subscriptions expire.

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 0%, so the description must carry the parameter burden, and it does: callback_url is an HTTPS URL that will receive Corbah's JSON event POSTs. It adds a protocol constraint the bare string schema lacks. It does not state whether the URL is validated or whether non-HTTPS is rejected.

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 concrete verb+resource ('Get notified when Corbah releases new products') and immediately explains the mechanism (POSTing JSON events to a callback URL). This clearly distinguishes it from the sibling unsubscribe_updates, which it even references via the unsubscribe token.

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?

Usage is implied by the purpose statement, but there is no explicit 'use this when you want X' guidance, no prerequisites, and no named alternative. The inverse sibling unsubscribe_updates is alluded to only indirectly through the returned token.

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