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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds billing behavior (priced B2, $0.05/call, included in Understanding and Influence) and frames itself as cross-catalog synthesis. That pricing/cost context is genuine behavioral value beyond the annotations, though return shape/pagination is not described.

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 purpose and 'read first' directive are front-loaded, and the pricing tail is compact. Every sentence carries information, though the pricing/billing sentence is somewhat tangential to selection and could be deferred to the referenced apis://prices resource.

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 does the work of telling the agent what to expect (corpus size, quarter vintage, top dimensions), which is enough to judge the tool's value. It is complete for a no-required-arg summary tool, missing only finer return details.

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?

The single optional 'context' parameter is fully documented in the schema (100% coverage), including that it is never used to rank. The description adds no parameter-level meaning beyond the schema, so the baseline of 3 for high schema coverage applies.

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?

It names a specific resource (the Insights root) and enumerates exactly what it reports — company count, quarter span, and top investment dimensions — which is a concrete verb+resource statement. It positions itself as the corpus-level entry point versus per-company tools, though it doesn't explicitly contrast with siblings like insights_dimensions or insights_adoption that could overlap on 'dimensions'.

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 imperative 'Read this FIRST' plus the rationale ('tells you the size and vintage of the corpus before you draw a conclusion from any single company') gives a clear when-to-use condition and sequencing guidance. It lacks explicit when-not-to-use or named alternative tools, keeping it short of a 5.

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