What's new (and what stopped)

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

With no annotations provided, the description carries the full disclosure burden. It does disclose genuine behavioral context: the two-list output structure and the emphasis that the stalled-items list is the primary value. But it never defines what 'もの' refers to (which entity type is listed), whether results are scoped to the active engagement, or how completed items are treated — meaningful gaps given annotations are absent.

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 front-loaded sentences per language: behavior first, then purpose emphasis. The bilingual duplication is justified by the ja/en/both output parameter, and the second sentence earns its place by explaining why the tool exists. Slightly longer than strictly necessary due to the bilingual format, but nothing is wasted.

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 simple tool (2 optional params, full schema coverage, no output schema), the behavior and parameter semantics are well covered. The main gap is the referent of 'もの' — an agent cannot determine what items appear in the lists (work packages, deliverables, findings?) or whether the query is scoped to the current engagement. A brief note on the entity type and scope would complete the picture.

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 coverage is 100%, so the baseline is 3. The description adds real value by clarifying that sinceDays plays a dual role: it defines both the 'recent' window for the first list and the stall threshold for the second ('未完了のまま N 日以上動いていない' / 'sitting unfinished for longer than that') — a relationship the schema's per-parameter description does not make explicit.

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?

The description uses a specific verb ('返す / List') tied to a concrete resource: items that moved in the last N days and unfinished items stalled N+ days. It goes beyond a bare statement by declaring that the second list is the point ('主目的は後者 — 止まっているものの発見'), giving the tool a distinct identity that separates it from status or dashboard siblings.

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?

Usage context is implied through '進捗報告で最も価値がある情報がここにある' (the most useful thing in any status report is here), which signals a status-report scenario. However, no sibling alternatives are named and no 'when not to use' exclusions are given, so an agent must infer when to choose this over next_best_action, get_dashboard, or check_engagement_health.

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