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

The description adds meaningful disclosure beyond the annotations: the tag is public, unverified, and enrolls no identity, and the intent is voluntary. That privacy/consent framing is valuable. But annotations already declare non-readOnly, openWorld, and non-idempotent; the description never addresses the non-idempotency implication (does calling twice create two tags?) or what is returned to be used later.

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 tight sentences with the core action and its privacy constraints front-loaded, and no filler. The phrasing is slightly indirect ("Optionally create... to correlate your reads and writes") but every clause carries information.

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-optional-param mutation with annotations and no output schema, the description covers what the tag is and its privacy posture. It does not explain the lifecycle: what identifier comes back, how that identifier is passed to subsequent reads/writes, or whether a tag can be ended or reused — which is the main thing an agent needs to actually use it.

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 description coverage is 0%, so the description must carry the parameter meaning. It only says "Intent is a voluntary category," which conveys optionality and non-enforcement but not what each enum value does or how intent affects the tag. The self-explanatory enum labels partially compensate, but the semantics remain thin.

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 gives a concrete verb+resource ("create a public, unverified visit tag") that clarifies the vague name begin_visit. It also states the effect ("correlate your reads and writes"), so an agent knows what it produces. It stops short of contrasting with the read_* siblings, which is a minor gap since none of them obviously overlap.

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?

"Optionally" signals the tool is not mandatory and that a visit may proceed without it, which is real usage context. However, there is no explicit when-to-use/when-not, no mention of the cookie/IP alternative in operational terms, and no guidance on whether to call it once per session or per operation.

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