Get expense

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds useful field-level context (cost code, reason) but says nothing about error behavior for an invalid expense_id or whether the record is scoped to a contractor. Adequate but with clear gaps for a read tool with annotations present.

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 the returned field set and followed by the sibling comparison. There is mild repetition between 'One expense with...' and 'Reads one ... expense', but no wasted content.

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 single-parameter read with full annotation coverage and full schema coverage, this is close to complete: it names the resource, the identifier, and the returned fields. Only minor behavioral details (invalid ID handling, scoping) are absent, and no output schema exists, so the field list is a helpful substitute.

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% and the single expense_id parameter is already documented as coming from list_expenses. The description reinforces the provenance ('Reads ... by expense_id') but adds no syntax, format or constraint detail beyond the schema.

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 ('Reads one Contractor Foreman expense by expense_id') and enumerates the returned fields. It explicitly differentiates itself from the sibling list_expenses by noting it adds the cost code and reason.

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 second sentence clarifies that this tool returns what list_expenses gives plus extra detail, which strongly implies when to choose it over the list tool. It stops short of an explicit 'use this when you need X, not Y' instruction but the routing signal is clear.

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