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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds one genuinely useful behavioral detail – the response includes debit and credit lines – but says nothing about missing-id behavior (404/null) or the response envelope shape.

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?

Two short sentences, front-loaded with what is returned. The trailing 'GET /journal_entries/{id}' is mildly redundant with the tool name and schema but does reinforce singular-by-id semantics at negligible cost.

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?

A simple single-parameter read tool with no output schema, and the description covers both what is fetched and the notable return content (debit/credit lines). Only error/empty-result behavior is unaddressed, which keeps it below a 5.

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% and the single parameter already carries a description ('Journal entry id.') plus type and positivity constraint. The description adds no format, range, or sourcing guidance beyond the schema, so the 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?

Specifies a clear verb+resource: fetches a single journal entry by id, and adds that the result includes its debit and credit lines. It implicitly contrasts with the singular-vs-list sibling (jurnal_list_journal_entries) but never names it, so differentiation is left to inference.

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?

Usage is only implied: 'One journal entry' plus a required id signals retrieve-by-id. There is no explicit statement of when to use this versus jurnal_list_journal_entries or a general ledger query, and no preconditions mentioned.

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