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

Annotations already flag destructiveHint=true and openWorldHint=true, but the description adds genuinely new context: the test actually delivers to real recipients and is rate-limited per workspace. That is exactly the kind of side-effect disclosure annotations cannot convey. It does not describe failure/response behavior, but no output schema exists to shift that burden.

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?

Two short sentences with zero filler, front-loading the action and following with the two consequences an agent most needs (real delivery, test quota).

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 one-parameter tool with rich annotations, the description covers purpose, real-world side effect, and rate limiting — enough to call it correctly. Minor gap: no mention of what a failed test looks like or whether the quota error is surfaced, though that is low-stakes here.

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?

Only one parameter with 100% schema description coverage ('Alert channel id.'), so the schema fully documents it. The description adds no extra meaning about the id (e.g. where to obtain it) but nothing is missing either; baseline 3 applies.

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 and resource ('send a test message through an alert channel') plus the intent ('check it works'), which cleanly separates it from the vs_channels_create/update/get CRUD siblings. An agent can identify exactly what this does without opening the schema.

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 phrase 'to check it works' clearly frames the use case, and the warning that it reaches real people/services implicitly rules out casual invocation. There is no explicit named alternative (e.g. 'use vs_channels_get to inspect config without sending'), so it stops short of full routing guidance.

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