read_document_chunk

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

Beyond the annotations (readOnlyHint=true, idempotentHint=true), the description discloses error behavior: it raises ToolFailure with DOCUMENT_NOT_FOUND/INVALID_PATH and includes a list of available paths in the error message. It also explains the return fields (content, total_lines, truncated). This additional context helps the agent anticipate failures and interpret responses, exceeding what annotations alone provide.

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 description is well-structured with clear sections (Args, Returns, Raises) and is appropriately sized. The core purpose is front-loaded in the first sentence, and the rest is organized logically. However, the Args section redundantly lists parameters that are already fully described in the schema, which is a minor inefficiency but not bloated.

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?

Given that an output schema exists (DocumentChunkResponse), the description still adds value by explaining error scenarios and the meaning of the response fields. It covers the essential context for correct invocation—path specification, line range semantics, and error handling. While pagination or performance limits are not mentioned, they are not necessary for a read tool with these annotations and output schema.

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 100%, so each parameter already has a detailed description, including examples and defaults (e.g., with_line_numbers for citation anchors). The description's Args section largely paraphrases these schema definitions without adding new semantic information. Thus, it meets the baseline but does not enrich parameter understanding beyond the schema.

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 opens with a clear statement of the verb and resource: "relative_path에 해당하는 문서 원문을 읽습니다" (reads the original document at relative_path). It further specifies chunked reading via line ranges, which distinguishes it from siblings like extract_document_outline (structural extraction) and list_target_documents (listing). The purpose is immediately understandable.

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 description provides a usage tip: "긴 문서를 통째로 읽어 컨텍스트를 낭비하지 않도록 줄 범위를 지정할 수 있습니다" (specify line ranges to avoid wasting context on long documents). This implies when to use line ranges, but it does not explicitly state when to prefer this tool over alternatives, nor does it mention exclusions or fallbacks. No sibling comparison is offered.

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