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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the aggregation semantics (counts grouped by state and category, not raw leads) and the underlying GET endpoint, but says nothing about cost, latency, or whether empty states are omitted. Some added value, not rich context.

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?

Three short sentences: what it returns, when to use it, and the endpoint. The return-shape detail is front-loaded and every sentence 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?

With no output schema, the description correctly compensates by enumerating the state buckets and mentioning category breakdowns. Minor gaps remain (whether zero-count states appear, or whether categories are user-defined), but an agent can call this confidently.

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 (list_id) and schema coverage is 100%, so the schema fully documents it. The description adds nothing about list_id beyond implying it scopes the stats; the baseline 3 applies when the schema does all the work.

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 states the resource (lead counts of a list) and the exact breakdown returned (state buckets plus category within each state), which is far more specific than the bare title. It is clearly distinct from siblings like myphoner_get_list or myphoner_list_leads, though it doesn't explicitly name them as alternatives.

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?

"Use it for campaign progress and conversion questions" gives concrete task contexts that select this tool over the raw list/lead endpoints. There are no exclusions or negative guidance (e.g., when to prefer myphoner_list_leads instead), so it stops short of a full 5.

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