Custom PDF MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that 'file_path' must be an absolute path, which is useful context not in the schema. However, it lacks details on permissions needed, error handling (e.g., for invalid paths), performance considerations (e.g., large file handling), or output format specifics beyond '包含文本内容、页面信息等的字典' (dictionary containing text content, page info, etc.). For a tool with no annotations, this leaves significant gaps in understanding its behavior.

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 appropriately sized and front-loaded, starting with the core purpose followed by parameter and return explanations. Each sentence adds value: the first states the tool's function, and the subsequent lines clarify inputs and outputs. There's no redundant information, making it efficient, though minor improvements in structure (e.g., bullet points) could enhance readability.

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 the tool's moderate complexity (3 parameters, no annotations, no output schema), the description is minimally adequate. It covers the basic purpose and parameter meanings but lacks details on behavioral aspects (e.g., error handling, performance) and output specifics. Without an output schema, the return value description ('字典' - dictionary) is vague. It meets the baseline for a read-only tool but doesn't fully address all contextual needs.

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 description adds meaningful semantics beyond the input schema, which has 0% description coverage. It explains that 'file_path' is an absolute path, 'page_numbers' extracts specific pages or all if None, and 'extract_tables' controls table data extraction. This clarifies the purpose and usage of each parameter, compensating well for the schema's lack of descriptions. However, it doesn't detail formats (e.g., array structure for page_numbers) or constraints (e.g., valid page ranges), keeping it from a perfect score.

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 tool's purpose: '读取PDF文件并提取文本内容' (Read PDF file and extract text content). It specifies the verb ('读取并提取' - read and extract) and resource ('PDF文件' - PDF file), making the function unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'get_pdf_info' or 'list_pdfs_in_directory', which likely serve different purposes (metadata retrieval vs. directory listing).

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 no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools or suggest scenarios where 'read_pdf_text' is preferred over 'get_pdf_info' (e.g., for full text extraction vs. metadata) or 'list_pdfs_in_directory' (e.g., for processing files vs. listing them). Usage is implied by the purpose but lacks explicit context or exclusions.

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