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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is largely covered. The description still earns credit for the non-obvious guarantee that 'proposed changes never run here', which is a behavioral claim the annotations do not express, plus the note that evidence is returned alongside the insight.

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, zero filler, front-loaded with the core action. The scoping constraint and the read-only guarantee are each stated once and earn their place.

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?

For a trivial single-parameter read tool with full annotation coverage, the description is sufficient and even hints at the return payload ('its evidence') despite no output schema. The only gap is the absence of any pointer on how the agent should source the insight_id.

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% for the single required insight_id parameter, including UUID format guidance, so the schema already carries the semantics. The description adds nothing about the parameter and merely implies its role through 'one insight', making the baseline 3 correct.

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 and resource ('Read one insight and its evidence'), which cleanly separates it from the sibling 'list_insights'. The scoping qualifier ('for the selected product, or an explicitly account-scoped insight') adds precision. It falls short of 5 only because it never names the alternative tool it is not.

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 establishes the calling context (product-scoped by default, account-scoped when explicit) but gives no explicit guidance on when to prefer this over 'list_insights' or how an agent should obtain a valid insight_id. Usage is implied rather than stated.

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