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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond that: the response is cached by Pirsch (implying possible staleness) and the endpoint is stateless with respect to date ranges and filters. It does not say how long the cache lasts, which is the main residual gap.

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 sentences, both front-loaded: what the tool returns first, then the behavioral quirks and the HTTP endpoint. No filler, no restatement of the title or of the schema, and every clause carries information the agent cannot get from structured fields.

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?

There is no output schema, so the description must carry the return shape, and it does by listing the five returned components. Combined with annotations that cover the read-only safety profile and a cached/no-filter caveat, an agent has enough to call it correctly; only the granularity of the time series and cache freshness are left unspecified, which is 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?

Schema coverage is 100% and the single domain_id parameter is documented in the schema with a pointer to pirsch_list_domains, so the baseline is 3. The description earns a bump by explicitly stating that no date range or filter parameters exist, which prevents an agent from assuming the filtering inputs that every sibling statistics endpoint accepts.

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 a concrete resource (an overview of a dashboard) and enumerates exactly what it returns: visitors, views, growth vs. previous period, a visitors time series, and team member count. It is clearly distinct in content from single-metric siblings like pirsch_get_totals or pirsch_get_growth, but it never names an alternative, so an agent must infer the routing rather than being told it.

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 establishes the context for use (a quick, one-shot dashboard snapshot) and states a real constraint — 'takes no date range or filters' — which tells the agent this is the wrong tool when a specific range or filter is required. It stops short of naming the sibling to use instead (e.g., pirsch_get_totals with a date range), so the when-not is present but the alternative is not.

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