mcp-pdf-tools

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 states the tool's function but fails to describe key behaviors: whether it handles large files, what happens with invalid PDFs, if there are rate limits, or the format of the output (e.g., JSON structure). This leaves significant gaps for an agent to understand operational constraints.

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 without unnecessary words. Every part earns its place by specifying the action and resource clearly, making it easy to scan and understand quickly.

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 (analyzing PDFs for statistics) and lack of annotations and output schema, the description is incomplete. It does not address behavioral aspects like error handling, performance, or output format, which are critical for an agent to use the tool effectively in real-world scenarios.

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 the schema already fully documents both parameters (file_path and top_n). The description adds no additional meaning beyond what the schema provides, such as explaining how word frequencies are calculated or what 'top words' entails. Baseline 3 is appropriate as the schema does the heavy lifting.

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 with specific verbs ('Get word count and top word frequencies') and resource ('from a PDF'), distinguishing it from sibling tools like pdf_extract_text (which extracts text) and pdf_info (which provides metadata). It precisely communicates what the tool does beyond just extracting or searching PDF content.

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 like pdf_extract_text (for raw text) or pdf_search (for specific content). It lacks any mention of prerequisites, such as needing a valid PDF file, or exclusions, leaving the agent to infer usage context from the tool name and purpose alone.

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