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

The description aligns with annotations (readOnlyHint=true, 'Read-only — it changes nothing') and adds substantial behavioral detail beyond them: it explains the return format (lines with account code/name, debit, credit, description), that it returns newest first with a cap and a `more` flag, and that it never returns the whole ledger without filters. This fully discloses the key behaviors.

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 description is detailed but every sentence earns its place: it opens with the purpose, then the return value, then filters, then the filter requirement, then order/cap/more, then the pairing, then read-only. It is well-structured, front-loaded, and avoids redundancy with the schema (e.g., it does not repeat the source enum list).

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?

Given the tool's complexity (15 parameters, no output schema), the description covers all essential aspects: what it searches, what it returns, how to filter, the caution against dumping the whole ledger, ordering, pagination via `more`, and its relationship to sibling tools. It also leverages the schema's 'NOT a filter' hints to prevent misuse. Nothing critical 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 coverage is 87%, so the schema already documents most parameters. The description adds a summary of filter categories (date, text, accountCode, source, amount) and clarifies that `text` matches memo AND line descriptions—but the schema already states this. It confirms how amount range is measured (total debits), but again that is in the schema. The description does not significantly augment the schema beyond an organizational overview, so a baseline of 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 ('Search') and a precise resource ('the general ledger's JOURNAL ENTRIES') and clearly distinguishes it from siblings by contrasting with search_expenses and search_documents. It also explains the return of balanced lines, so an agent can tell exactly what this tool does relative to others.

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?

Explicitly states when to use ('Pairs with search_expenses for reconciling') and when not to ('This never dumps the whole ledger' implies filters required). It also lists concrete filter combinations and provides alternatives via 'NOT a filter' parameter hints, which guide the agent to `text` or `accountCode` instead. This gives clear context but could have stated explicit exclusions more directly.

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