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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world. The description adds genuinely new context: the 30-day default window, the São Paulo timezone interpretation, and the guarantee that no personal data is returned — a privacy-relevant disclosure not available in structured fields.

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?

A single dense paragraph with semicolon-delimited clauses; purpose and the two modes are front-loaded and every clause carries information. Slightly heavy as one block, but no wasted sentences.

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 carries the burden of describing returns — and it enumerates them (totals, daily series, per-step funnel, origins, per-link summary). Combined with default window and timezone, an agent has everything needed to call and interpret 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 coverage is 100% (baseline 3), but the description goes further by explaining the semantic consequence of tourId (per-tour detail vs. per-link summary) and supplying the implicit default for from/to that the schema does not state.

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 resource ('Estatísticas do link permanente') and splits behavior into two clearly described modes (with vs. without tourId), naming exactly what each returns. An agent can tell this is the read-only analytics tool with no ambiguity against the mutation-oriented siblings.

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?

Explicitly conditions usage: pass tourId for per-tour analytics, omit it for a per-published-link summary, and states the default window when no dates are given. No alternative tool is named, but none exists in the sibling list, so the guidance is sufficient.

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