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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), but the description adds real value beyond them: it requires a Siteiz Pro API key via Bearer header, and it discloses that results depend on the latest scan and include unindexed-looking pages the scan may not have covered. It doesn't say what happens when no scan exists or how stale the scan may be.

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?

Two sentences, front-loaded with what the join produces, then usage and auth prerequisite. The first sentence is dense with parenthetical caveats but every clause carries information; minor trimming possible but nothing is wasted.

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?

Covers data sources, output composition, intended decision use, and an auth prerequisite; an output schema exists so return values needn't be spelled out. For a low-parameter read tool this leaves an agent with everything needed to call it and interpret results.

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?

Only one optional parameter (site), and schema description coverage is 100%, so the schema already explains the host format and the optional-when-single-site behavior. The description contributes nothing additional about the parameter, which is the expected baseline when the schema does the work.

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 precise operation: joining Search Console impressions with the latest Siteiz scan to produce pages ranked by real Google impressions, each with AI readability score and open fixes. It also names the edge-case content (no-impression pages, pages the scan missed) so an agent can distinguish this from siblings like get_search_performance or get_ai_visibility_report without opening a schema.

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 clear decision context — "Use it to decide what to fix first" — which tells the agent the intended outcome (prioritization). It does not name explicit alternatives or say when not to use it (e.g., versus raw search performance), so it stops short of full routing guidance.

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