get_traffic_by_country_tool

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

With no annotations, the description carries the full behavioral burden. It implies a read via "Get" and usefully documents defaults (30 days ago, today, 20 countries) and the mutual exclusivity of zone_id/zone_name, but says nothing about permissions, rate limits, pagination of country results, or ordering. Adequate but thin for a zero-annotation tool.

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 one-line purpose, then the mutual-exclusivity rule, then structured Args/Returns blocks. Every line is scannable and earns its place; minor redundancy between "default: 30 days ago" prose and the schema defaults, but not wasteful.

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?

An output schema exists, so the brief Returns note is sufficient rather than required. For a parameterless-required, read-only analytics query the description covers invocation adequately; the only real gap is sibling/alternative guidance and any pagination or rate-limit behavior.

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 has to compensate and does: it documents every one of the five parameters including type hints (32-character hex zone ID, domain zone name, ISO date format) and the defaults for since/until/limit. This is meaningfully more than the bare schema provides.

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+resource ("Get traffic breakdown by country") that distinguishes it from analytics siblings like get_top_pages_tool and get_zone_analytics_tool by naming the grouping dimension. However, it never explicitly contrasts itself with get_zone_analytics_tool, so the differentiation is inferential.

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?

Gives a concrete usage rule — "Provide either zone_id or zone_name, not both" — which prevents a real invocation error. It does not, however, say when to prefer this tool over get_zone_analytics_tool or get_top_pages_tool, so alternative routing is absent.

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