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

Annotations already indicate a non-read-only operation (readOnlyHint=false). The description adds useful behavioral detail: it returns a file_id for chaining and a ~1h download URL, which hints at the output being a new file with a time-limited link. It does not contradict the annotations and adds context about the result format.

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, compact sentence that front-loads the core action and includes the essential return information. No redundant words or filler; every element 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?

For a simple rotation tool with full schema coverage and no output schema, the description covers the core behavior and return values (file_id and URL). It does not mention potential edge cases like file size limits or whether the original is modified, but these are minor for the operation's simplicity. Overall, it is sufficient for an agent to call the tool correctly.

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 coverage is 100%, so both parameters are already described in the schema. The description does not add any extra semantic detail beyond what the schema provides (e.g., it repeats the degrees values but does not explain the pdf parameter further). Baseline 3 is appropriate given full schema coverage.

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 states a clear verb ('Rotate'), the specific resource ('every page of a PDF'), and the exact degrees (90, 180, 270 clockwise). It is immediately obvious what the tool does and it is distinct from sibling PDF operations like merge or split.

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 clearly implies the tool is used when rotation is needed, but it does not explicitly state when to prefer this over alternatives, nor does it mention any exclusions or prerequisites. No explicit routing to other tools is provided.

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