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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, and the description stays consistent while adding real behavioral context beyond them: 'Nothing is changed and no model runs' signals no side effects and no LLM cost, and it discloses the output split between inline counts/trial-balance diffs and a handle enumerating every differing record. It stops short of noting limits such as book size or performance.

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 purpose is front-loaded and no sentence is pure filler, but the middle is a single long semicolon-chained sentence enumerating matching keys for entries, accounts, parties, registers, documents and trial balances, which is hard to parse. That rule set is genuinely needed, yet it would read far better as a list, and some detail could be trimmed.

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 high-complexity comparison tool with nested object inputs, five parameters and an output schema, the description covers input modes, grouping/matching semantics, order-insensitivity, and the shape of the return (inline counts plus a handle). With annotations carrying the safety profile and the output schema carrying return-value detail, nothing an agent needs to invoke it 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%, so both the handle/inline exclusivity pairs and workspace_tag scoping are already documented in structured fields. The description restates the handle-or-inline choice in prose but adds no syntax, format, or constraint details beyond the schema; baseline 3 is appropriate.

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 verb and resource ('compare two Standard Books documents') and pins the comparison basis precisely: semantic content rather than shared ids. The 'same_identity' vs 'same_content' framing makes the tool's role distinctive among siblings like report_standard_book or invert_standard_book, though no sibling is named directly.

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 explains the selection between the two input modes ('Supply each book by transfer handle or inline (first_handle or first_book, second_handle or second_book)') and gives a concrete motivating case (an export versus a workspace book after submission). It does not state when to prefer this over alternative reporting/inspection tools, so no exclusions are offered.

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