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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: the accepted input range (1 to 1,000), the concrete return payload (sheet count, blank pages added, per-side order, CSV), and the hard boundary that no PDF is produced. It stops short of noting any cost or side-effect nuances, which keeps it at 4 rather than 5.

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?

It is front-loaded with the trigger condition and the exclusion sits at the end where it belongs, with zero filler sentences. The middle sentence is long and comma-chained, packing the parameters and return values together, which slightly hurts scannability but wastes no words.

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?

With an output schema present, the description need not document return values, yet it still summarizes them; all three parameters are fully documented in the schema; and the sibling boundary is stated. Nothing an agent needs to select and call this tool correctly is missing.

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% and the schema already spells out the booklet/2up/4up meanings and left/right binding semantics in more detail than the description. The description only restates the option names and the page range, adding no new syntax or edge-case meaning. Baseline 3 applies when 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 names a specific verb and resource ('Plan booklet page order', 'which pages go on which sheet') and explicitly distinguishes itself from the only sibling by stating it works 'without a file' while make_booklet requires one. An agent can route between the two without opening either schema.

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?

It gives explicit trigger conditions ('when the user asks which pages go on which sheet... how many sheets a booklet needs, or how many blank pages') and an explicit exclusion with the named alternative ('Does not make a PDF (use make_booklet with the file for that)'). Both when-to-use and when-not-to-use are covered.

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