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

Annotations already declare a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the safety profile is covered. The description adds useful shape about the return (grouped by message with occurrence/session/page counts), but says nothing about limits, permissions, or ordering. Adequate given the annotation coverage, not rich.

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?

A single tight sentence that front-loads the resource and then the aggregation and output dimensions. No filler, no restatement of the name.

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 a fully described schema and annotations carrying the safety profile, the description gives enough to call the tool correctly and hints at the return shape in lieu of an output schema. Only the missing usage/alternative guidance keeps it from being complete.

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%, so every one of the 8 parameters (dates, period enum, limit, filters syntax, timezone, segment) is already fully documented in the schema. The description adds no parameter meaning beyond that, so the baseline 3 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?

States a specific verb and resource ('get ... JavaScript errors') and adds the aggregation grain plus the key output dimensions (occurrences, affected sessions and pages). It clearly stands apart from sibling breakdown tools, though it never names an alternative to contrast with.

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?

There is no when-to-use guidance at all: nothing says when error reporting is the right call versus get_breakdown, get_events, or get_journeys, nor any prerequisite or exclusion. The agent must infer usage purely from the scope of the resource name.

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