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

Annotations already carry the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the description only needs incremental detail — and it supplies two useful facts: the report returns each account with its entries and balance, and entries reference the source receipt. It also discloses the auth prerequisite (a Cotlet API key with access to this app), which annotations do not cover.

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 resource and period, then adds return shape, then usage intent, then auth — a sensible order with no redundancy. The 'without opening the report by hand' clause is mild flavor rather than necessary information, keeping it just under a 5.

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 no output schema, the description carries the burden of describing returns and does so at a high level (accounts, entries, balances, receipt linkage). It is sufficient for correct invocation, though it says nothing about report size, pagination, or whether large periods truncate.

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 three parameters (account, date_from, date_to) are already documented with formats. The description adds only the scoping idea 'by account', which the schema's own 'Limit to one account number' already conveys. Baseline 3 is correct.

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 — the general ledger report for a period, broken out by account — and even parallels it to the in-app location 'Reports > General ledger'. That is enough for an agent to tell it apart from the sibling list_journal_receipts and the invoice-list tools 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?

Gives a concrete usage context ('hand the books to an accountant'), which tells the agent this is an export/period-reporting tool rather than an operational one. It does not name an alternative or state when-not to use it, so it falls 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.