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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds real operational context: hourly cache serving, refresh cost (slow, up to a minute), a potential third-party DataForSEO spend when Search Console is unconnected, and the write-vs-read credential gate on refresh. That is behavior an agent cannot infer from annotations or 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?

Long but front-loaded: purpose first, then metrics inventory, then the 'call this first' guidance, then caching/refresh caveats, then the sibling redirect. Every clause carries information, though the metric enumeration is dense enough that a shorter summary would scan faster.

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?

No output schema exists, so the description must describe returns, and it does so by listing the exact blocks the overview contains and what includeChart adds. Combined with caching, cost, and credential notes, an agent has everything needed to call and interpret this 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?

Schema coverage is 100%, so the baseline is 3; the description nonetheless adds meaning the schema only hints at, namely that refresh is ignored unless the caller has write credentials and that includeChart returns daily traffic, ranking and AI-mention series specifically. These are consequence-level details beyond the one-line schema descriptions.

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 verb+resource ('The Blawgy Overview page for one site in a single call') and enumerates the payload (publishing status, headline metrics for trailing 90 days vs prior 90, recent wins, next publish, to-dos). This is unmistakably distinct from siblings like get_traffic or get_seo_snapshot.

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 an explicit trigger ('Call this first when asked "how is the site doing"') and an explicit alternative plus condition ('For a custom date range use get_traffic'). It also states the credential prerequisite for refresh, so the agent knows when the call will silently serve cache instead.

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