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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds that access is free (no paid tier/credential implied) and enumerates the topics covered, but it never states the response form (prose docs vs structured JSON) or whether it is static.

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?

One short sentence with the key qualifier ('FREE') front-loaded and no filler. It is a bare fragment rather than a complete clause, which costs a little readability but wastes nothing.

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?

With no output schema and no parameters, the description must convey what comes back, and enumerating the covered topics is a reasonable proxy. However, it omits the return format and whether the content is a static doc or live data, which is exactly what an agent needs to plan the next call.

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 tool takes zero parameters, so the baseline applies; there is nothing for the description to disambiguate. Mentioning endpoint names within the description content is a small bonus but not parameter guidance.

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 names the concrete subject matter — alert topics, default thresholds, signature verification, and the test/unsubscribe endpoints — so an agent knows this returns reference information about webhook alerts. The 'FREE' prefix and title distinguish it from the paid subscription siblings, though the description never says outright that it returns documentation rather than live alert data.

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 only implied: read this before calling alerts_subscribe_week or alerts_subscribe_month. Neither sibling nor any precondition is named, and there is no explicit when-not-to-use. The 'FREE' framing is the only routing signal.

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