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

Adds substantial context beyond the annotations: the entry gets type 90 (Other), opening balances cannot be created, debits and credits must balance, it writes to the ledger, requires the user's Cotlet API key, and confirms each call by default. With readOnlyHint=false and destructiveHint=false already declaring the safety profile, this enriches rather than repeats.

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-loads the purpose and then lists constraints compactly. One sentence ('Books one general journal entry with its lines') restates the opening sentence and is mildly redundant, but no other filler.

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 with no output schema, the description covers constraints, auth, and the write target, which is enough to call it correctly. It stops short of anything about the return payload, but with no output schema declared that gap is minor.

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 all four parameters (lines, division, entry_date, description) are already documented in the schema. The description adds a balancing constraint relevant to 'lines' but no syntax or format detail beyond the schema, so baseline 3 applies.

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 ('Book a general journal entry with debit and credit lines') and scopes it to a single general journal entry, which distinguishes it from the sibling create_purchase_entry and create_sales_invoice tools. An agent can tell what it does without opening the 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 operational context (per-call confirmation, API key requirement) and implies usage, but never states when to choose this over the other bookkeeping siblings such as create_purchase_entry or create_sales_invoice. The guidance is real but partial.

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