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

Annotations already signal non-read-only, non-destructive, non-idempotent behavior. The description adds 'permanently,' which clarifies that rotation is baked into the output rather than a transient view. This is still a bit ambiguous about whether the original file is replaced or a new file is produced, and it does not describe result delivery.

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?

Two short sentences with no filler. The core action and degree options come first, and the useful context appears second. Every phrase earns its place.

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 schema documents all parameters, and the description provides a clear use case. The main omission is an explicit note about the return value or whether the input file is replaced, but the output_filename parameter implies a resulting file.

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 baseline is 3. The description mostly restates what the schema already says about angle (90, 180, 270 clockwise) and adds no extra meaning for file, pages, or output_filename.

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 uses a specific verb-resource pair ('rotate pages of a PDF') with exact degrees and direction. It is inherently distinguishable from siblings like reorder_pdf_pages, remove_pages, and split_pdf.

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 gives a clear use case: 'sideways or upside-down scans.' It does not explicitly name alternatives or say when not to use the tool, so it stops short of full routing guidance.

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