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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds a genuinely useful prerequisite not in the schema or annotations: 'Only sites whose owner added mttr in Search Console have any' — an agent needs this to interpret empty results. It also sketches what the result contains (clicks by day, totals vs prior days, pages ranked by loss).

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 content is essentially a few run-on sentences with broken grammar ('the totals against as many days before'), forcing the reader to re-parse clauses. Key facts are present but not front-loaded or cleanly separated, so structure costs readability.

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 must convey what is returned, and it does attempt that (clicks by day, totals vs baseline, per-page deltas). But the garbled phrasing and missing pagination-return detail leave an agent partially guessing about result shape.

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%, so the schema already documents show/site/limit/offset, making 3 the baseline. The description reinforces 'show' by tying 'lost most first' to the default-ish lost ranking, but adds no format or interpretation detail beyond what the schema states.

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 first sentence identifies the resource (clicks from Google search via Search Console), and the description branches clearly into a no-site mode and a with-site mode. However, the language is heavily tangled ("the searches nothing on two or more of the sites answers") and never states a clean verb+resource, so an agent must decode intent rather than read it. Siblings like mttr_queries or mttr_pages are not named or distinguished.

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 site vs no-site branches imply when each shape of result applies, and "A baseline to judge a change by" hints at the use case. But there is no explicit when-to-use-vs-alternatives guidance and no exclusions relative to the many sibling traffic/query tools.

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