document_info

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

With no annotations, the description carries the full burden of behavioral disclosure. It states what metadata is returned (file type, size, modification time) and notes variations (PDF metadata, line counts for text files), which is helpful. However, it does not mention error conditions (e.g., missing file, insufficient permissions), time-out behavior, or any side effects, leaving some behavioral uncertainty for the agent.

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 concise and front-loaded: the first sentence states the core purpose, the second lists the main outputs, and the Args section cleanly describes the parameter. Every sentence contributes value with no fluff or redundancy.

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?

The tool is simple (one param) and an output schema exists, so return values are covered externally. The description logically describes the metadata returned and file-type-specific additions. It lacks guidance on edge cases like unsupported file types or empty results, but completeness is adequate for a metadata retrieval tool. A minor gap is not explicitly stating what happens for non-PDF binary files, but the description's inclusive language ('Includes file type...') gives sufficient context.

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?

The schema description coverage is 0%, so the description must add meaning to the single 'path' parameter. It does add the constraint 'File path inside the allowed root', which is valuable. However, it does not specify path format (absolute vs relative), whether directories are valid, or any path syntax details. This is a partial compensation but not comprehensive.

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 clearly states the verb 'Return' and the resource 'metadata for a document', distinguishing it from sibling tools like read_document (which reads full content) and list_documents (which lists documents). The explicit 'without reading its full content' clarifies the scope and separates it from content-reading tools.

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 implies when to use this tool—when you need metadata rather than content—by explicitly stating it returns metadata and not content. It does not name specific alternatives or exclusions, but the context of the sibling tools and the phrasing 'without reading its full content' gives clear contextual guidance without explicitly saying 'use read_document instead'.

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