OpenPanel: Get realtime stats

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

Because readOnlyHint=true already declares this a safe read, the description's added burden is lower. It does disclose that the count is live/real-time rather than historical, which matters given the absence of an output schema. It says nothing about refresh cadence, rate limits, or the shape of the returned count.

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?

It is a single front-loaded sentence with no filler, although the '[UNIFIED]' tag is unexplained noise. Within one line it states the metric and the data source, so it is tight, if sparse.

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 tool with two undocumented parameters, no output schema, and only a readOnly annotation, the definition is too thin. It never covers what the parameters mean or what the response contains, so an agent would have to guess at invocation details.

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?

Both parameters, including the required `site` and the nullable `project_id` with a default, have 0% schema description coverage, so the description must explain them, and it explains neither. It never mentions site or project scoping, so an agent cannot tell from the definition what site resolves to or when project_id is needed.

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-plus-resource: it returns a real-time active visitor count. That is far more specific than a restatement of the name, and it distinguishes the tool from adjacent stats tools. However, it draws no explicit boundary against siblings such as openpanel_get_usage_stats or get_rate_limit_stats, and the '[UNIFIED]' prefix is opaque.

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 description gives no guidance on when to use this tool rather than the many other stats tools, and states no prerequisites or exclusions. 'Via Insights live API' hints at a live data source, but it does not tell an agent which conditions should lead it to pick this tool.

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