MCP PDF Reader

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

No annotations are provided, so the description carries the full burden. It states the tool lists images with metadata, but does not disclose behavioral traits such as error handling (e.g., what happens if the file path is invalid), performance considerations (e.g., speed for large PDFs), or output format details (e.g., structure of the returned list). This leaves significant gaps for a tool with no annotation coverage.

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 a single, efficient sentence that front-loads the core purpose ('List all images embedded in a PDF file') and adds essential detail ('with their metadata (page, dimensions, type)'). There is no wasted verbiage, making it highly concise and well-structured.

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 (listing embedded images), no annotations, and no output schema, the description is minimally adequate. It specifies what the tool does but lacks details on output structure, error conditions, or performance. This leaves the agent with incomplete context, though the core functionality is clear.

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 100%, with the parameter 'filePath' fully documented in the schema as 'Absolute path to the PDF file'. The description does not add any meaning beyond this, such as file format requirements or path examples. With high schema coverage, the baseline score of 3 is appropriate as the schema handles the parameter documentation adequately.

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 specific verb ('List') and resource ('images embedded in a PDF file'), and distinguishes it from siblings by specifying the scope ('with their metadata (page, dimensions, type)'). This differentiates it from tools like 'get_pdf_metadata' or 'read_pdf' that handle different aspects of PDFs.

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 does not mention sibling tools like 'extract_pdf_image' (which might retrieve actual image data) or 'search_pdf' (which might find text), leaving the agent to infer usage context without explicit direction.

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