mat_overview

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

No annotations are provided, so the description carries the full burden; 'Show' does imply a non-destructive read of an existing heapdump, which the agent can infer. However, it never states the prerequisite that a heapdump must already be opened (report_id from open_heapdump) or what happens on an invalid/closed report — material gaps for a tool positioned as the mandatory first step.

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 statement is front-loaded and dense with useful specifics, and the ordering rule follows immediately. The only waste is the full bilingual repetition, which doubles length without adding information for a single reader.

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?

An output schema exists, so return values need not be described, yet the description still summarizes them, plus it establishes the call-first convention. What is missing is the lifecycle context: that it operates on a heapdump opened via open_heapdump and requires a valid report identifier.

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 0% and the single parameter report_id is never mentioned in the description — not its meaning, nor where to obtain it (presumably from open_heapdump). With no schema text to fall back on, the description should have explained this identifier, so it fails to compensate for the coverage gap.

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?

Specific verb 'Show' plus the resource 'heap overview', followed by an explicit enumeration of contents (used/committed/live heap, object/class/classloader counts, JDK version, leak suspect count). This makes it clearly distinguishable from siblings like mat_histogram, mat_dominator, and mat_leak_suspects, which cover subsets of these facts.

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?

'Always call this first to understand a heapdump' gives an explicit ordering rule relative to every sibling, which is strong actionable guidance. It stops short of naming exclusions or follow-up paths (e.g., 'then use mat_leak_suspects for suspect detail'), so it is clear context without full alternative routing.

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