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

Annotations already declare readOnlyHint and non-destructive behavior, so the description correctly focuses on scope instead: what is measured, what is excluded (paid, GA4, total site visits), and the default period. It adds no information about data freshness or attribution lag, which is the one behavioral trait an agent might still need.

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?

The scope statement is front-loaded, the metric list is compact, and the exclusion clause is placed at the end where it belongs. The list of quoted trigger keywords is slightly verbose but earns its place for routing.

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 an output schema, full annotation coverage, and one well-documented optional parameter, the description is nearly complete. Only data-freshness/caching behavior is unaddressed, which would matter for a time-sensitive reporting tool.

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?

There is a single parameter with 100% schema description coverage including examples and default, so the schema carries the full burden. The description adds nothing about date_range format or constraints, which is acceptable at this coverage level (baseline 3).

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 specific verb+resource (site visibility in organic Google results) and enumerates the exact metrics returned: clicks from search, impressions, CTR and average position. It explicitly excludes paid traffic and GA4, which cleanly separates it from siblings like get_analytics_summary and get_google_ads_summary.

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 gives concrete trigger phrasing ("SEO", "posicionamiento", "ranking", "búsquedas orgánicas", "aparecemos en Google") and a negative condition ("No mide visitas totales al sitio"), which is strong routing guidance. It does not name an alternative sibling tool for total-traffic questions, so the agent has to infer that get_analytics_summary is the fallback.

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