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

Annotations only say readOnly and closed-world; the description goes well beyond them by explaining that duplicate names produce separate rows, defining each result field's meaning, and disclosing the null-entity_id edge case (unconfirmed report bundles only lookupable by name). That null case is exactly the kind of behavioral trap the description must surface, and it does.

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 action, then result fields, then downstream usage — a logical order with no filler sentences. It is a single dense block mixing three concerns, so it is slightly hard to scan, but every clause carries information.

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 must explain the return shape and it does, field by field, plus the downstream identifier contract and the null-entity_id caveat. For a one-parameter search tool that is the complete set of things an agent needs to call it and act on its output.

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 0% for the single `query` param, so the description must carry it; it does by clarifying the param is a person/company name and that Korean spellings are accepted and resolved to English filer names. It adds no info on partial matching, minimum length, or ambiguity handling, so it compensates but not exhaustively.

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?

Names a concrete verb (find) and resource (holder: institution / asset manager / individual) and scopes it to name-based lookup, which separates it from the sibling ID/history tools. It also previews the returned shape (kind, role, key_hint, top, corps), so an agent knows exactly what kind of result to expect.

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?

Explicitly states the input condition (search by name, Korean input resolved to English filer names) and, critically, tells the agent to chain the returned entity_id into get_portfolio / get_recent_changes / get_holder_history. It does not contrast itself with search_symbol or explain what to do when a name yields many rows, so it stops short of full when/when-not guidance.

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