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

With no annotations, the description must carry behavioral burden. It usefully discloses the collection bounds (1–1095), exactly which fields are searched, and the bilingual query tolerance. However it says nothing about result ordering, match semantics beyond the schema's AND note, or what a hit contains, and never explicitly confirms this is a read-only operation.

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?

Three short sentences, front-loaded with the resource and scope. The parenthetical clarifying that 'subtitle' includes the separator sentence is the one dense detail, and it earns its place by resolving a domain ambiguity. Slight redundancy between the opening 'by word' and the later field list, but no filler.

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 3-parameter search tool with no output schema and no annotations, the description covers input scope well but leaves the return side unaddressed, and gives no hint about how to escalate from a broad query to fetching a specific paper with get_paper. Adequate but with a clear gap on results and on sibling handoff.

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%, with per-parameter descriptions, defaults, enum values and example terms, so the baseline would be 3. The description adds genuine meaning beyond the schema by stating that queries may be issued in Japanese or English, which is a substantive semantic fact about the query parameter that the schema does not convey.

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 plus a concrete scope: word-search over Yamagishi Lab's mathematical physics papers numbered 1–1095, across title, subtitle (including the separator sentence), keywords and abstract. That is far more specific than a name restatement. It never names the sibling get_paper (single-paper fetch) to draw the retrieval boundary, but the search-vs-fetch distinction is strongly implied by the name and the 'by word' framing.

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 only usage guidance is 'Japanese or English both fine', which tells the agent the query language is unconstrained. There is no statement of when to prefer this over get_paper or list_separators, and no guidance on what to do with an empty result set. Usage is inferable from the tool name but not explicitly routed.

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