Summarize hidden surfaces (what is hiding)

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantial context beyond them: each executor call is guarded and pcall'd, unavailable functions are surfaced in `unavailable` instead of aborting the whole summary, cost=medium, and it requires an active-client. Partial-failure behavior and prerequisite are exactly the kind of traits structured fields cannot convey.

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?

Front-loaded with the purpose and enumerated counts, but the trailing block is padded and partly redundant: 'idempotency=read-only' and 'Safety: read-only' duplicate each other and the annotations, and 'On failure: inspect tool-schema...' is boilerplate. Those sentences do not fully 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?

With no output schema, the description does the work of describing the return shape (counts per category, top-classes breakdown, `unavailable` list) plus prerequisites and failure handling. It is complete enough for a read-only aggregate, though it could note output field naming conventions more precisely.

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?

Only one optional param (threadContext) with 100% schema coverage; the schema already explains it fully. The description merely repeats the signature '{ threadContext: number? }' without adding new semantics, so baseline 3 is appropriate.

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 ('One-call high-level overview answering what is hiding in this game?') and then enumerates exactly what it counts: Actors, nil-parented instances, running scripts, loaded modules, and hiddenScripts. It clearly positions itself as the aggregate entry point that feeds deeper 'hidden-*' siblings, so an agent can distinguish its role from individual finders.

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?

'Use this first to decide which deeper hidden-* tool to run next' gives explicit ordering guidance and names the sibling family it routes to. It lacks named exclusions (e.g., when NOT to bother with the summary vs. a direct finder), but the entry-point framing is clear.

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