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

Annotations already declare readOnlyHint=true, establishing this is a safe read operation. The description adds behavioral context by detailing the analytics dimensions returned, which helps the agent anticipate the tool's output and scope. It does not cover potential rate limits or aggregation delays, but those are not critical given the annotation and output schema.

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 description is two sentences, front-loaded with the core purpose and scope, followed by a useful sibling alternative. Every clause earns its place with no redundancy or fluff.

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?

The output schema already covers return values, so the description need not enumerate them. The provided description adequately conveys scope, the distinction from a sibling tool, and the key data categories, making it complete enough for a tool with only two parameters and a read-only annotation.

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 100%, with both parameters thoroughly documented: siteId references list_sites, and source explains 'Direct', example values, and where to get valid values (trafficSources). The description itself adds little parameter-level meaning beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 uses a specific verb and resource ('Get analytics for one website') and enumerates the returned metrics: visitors, views, traffic sources, per-page breakdown, leads, and revenue. It also distinguishes itself from sibling tools by noting the website-level scope and directing page-level needs to get_page_analytics.

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?

The description explicitly gives an alternative for a different use case: 'For a single standalone page use get_page_analytics instead.' The 'one website' scope also implicitly distinguishes it from get_workspace_analytics, making it clear when this tool is the right choice.

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