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

Annotations only declare the generic write profile (readOnlyHint=false, destructiveHint=false, non-idempotent). The description adds real behavioral context beyond that: entries must balance, must land in an open period or be rejected, accruals marked reverse:true self-reverse on the 1st of the following month, and an explicit "Effects" line stating what is created.

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?

Front-loaded with purpose and the core constraint, and the closing "Effects" line is useful. Slightly redundant: the 1st-of-next-month reversal is explained twice, and the kind-of-account explanation repeats the enum description.

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 mutation tool with no output schema, the description covers the important ground: preconditions (open period), validation (must balance), side effects (auto-reversal), and what gets created. It stops short of saying what the call returns (e.g., the created entry identifier), which matters slightly more given there is no output schema.

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 the baseline is 3, but the description adds interpretive meaning: each line names an account "in their words" plus its kind so statements can place it, debit/credit must balance, and reverse:true is tied to the next-month-1st behavior in prose. The date/memo semantics are largely restated from the schema, so it does not reach 5.

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?

States a specific verb and resource (record an adjusting entry) and immediately concretizes it with examples: "an accrual, depreciation, a correction." It is clearly distinguishable from the neighboring gl_entry/gl_journal/gl_void_entry family because it is scoped to period-close adjustments with a reason and a balancing requirement.

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?

Gives explicit operating conditions: record only "when the accountant or the person gives the figures, never invent an amount," and "A period that is already closed takes no entries: date it in the open period." It does not name a sibling alternative (e.g., a plain journal entry tool) to route the agent elsewhere, which keeps it short of a 5.

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