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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds value beyond that by disclosing what comes back in the record (amount in NZD with GST, indicative deductions, reconciliation state with the bank), which is the kind of detail annotations cannot carry.

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?

A single sentence with the purpose front-loaded, followed by the field inventory. The trailing field list is long but each item earns its place given there is no output schema; only minor tightening would be possible.

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 field enumeration is what makes the return shape knowable, and it covers the record thoroughly. The only missing piece is any hint about error behavior when an id is invalid or belongs to another organisation.

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 both income_id and organisation_id are already documented in the schema. The description reinforces the id provenance ('from list_income') but says nothing about organisation_id or the single-vs-multi-organisation conditional, so baseline 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?

States a precise verb+resource (retrieve one income record by id) and enumerates the exact fields returned, which distinguishes it cleanly from list_income and from the sibling get_expense_record. It also anchors the id source to list_income so the agent knows the retrieval path.

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?

The phrase 'by its id from list_income' implies the precondition that you must first have an id from a listing call, which is useful usage context. However, it never says when to prefer this over siblings like get_income_history or get_expense_record, and it names no exclusions.

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