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

The description adds valuable behavior beyond annotations: credit cost, 100-page input limit, 10-minute output expiration, and the warning that rewriting can invalidate digital signatures. This is especially useful because readOnlyHint=false and destructiveHint=false do not fully convey the mutating side effects.

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?

Four short sentences, each earning its place: purpose, cost/limit, expiration, and side-effect warning. Information is front-loaded and there is no filler or redundancy.

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 description covers important operational context like cost, limits, expiration, and signature invalidation. However, with no output schema it does not describe the return value or where the rotated file is delivered, and several parameters remain semantically undocumented.

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 only 14%, so the description must compensate, but it only lightly maps 'degrees' and 'pages' without specifying allowed values or formats. It does not explain fileIds, requestId, title, author, or subject semantics, leaving most parameters dependent on the raw schema.

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 specific operation ('Rotate one PDF clockwise by degrees') and resource ('one PDF'), and clarifies the optional scope ('pages selects a subset'). This clearly distinguishes pdf_rotate from sibling tools like pdf_merge, pdf_split, and pdf_compress.

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 makes the use case clear: rotate a single PDF by a specified angle, optionally on selected pages. It does not explicitly name alternatives or exclusions, but no sibling tool competes for the same operation, so the context is sufficient.

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