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

Annotations only declare write/non-destructive; the description goes far beyond by disclosing first-run account creation, idempotency (existing account unchanged), the created/exists response signal, the 60-minute welcome-email password link that fires only in the created branch, and the automatic scans that follow. This is exactly the behavioral context an agent needs and cannot get from structured fields.

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-loads the core action and keeps detail proportional to the tool's real complexity (idempotency, email timing). The parenthetical source-code confirmation and timestamp are slightly verbose but they substantiate a behavior an agent must not misreport, so nearly every sentence earns its place.

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, the description compensates by explaining the created/exists response and the downstream scan tools, which is enough to call and interpret it. It omits auth/permission requirements and error cases, leaving only a minor gap.

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 ('domain') with 100% schema description coverage, so the schema already documents it fully. The description adds no format or syntax detail beyond 'für eine Domain', so the baseline of 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 ('Aktiviert') and resource ('turbometrics'), plus its scope ('für eine Domain') and what the product is (kostenlose Performance-Überwachung für turbopress-Kunden). This clearly separates it from sibling monitoring tools like start_performance_scan and get_performance_score.

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 explains the activation workflow and names the follow-up tools (get_performance_score, get_performance_findings), which implies the usage context. However it never states explicitly when to choose this tool over alternatives (e.g. start_performance_scan) or any preconditions, so guidance is implied rather than explicit.

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