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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safe read nature is covered. The description adds genuine behavioral context beyond annotations by clarifying the data is live from the ledger and that get_financial_summary reads a processed snapshot — which shapes expectation about freshness. No contradiction with annotations.

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 content is front-loaded with the core purpose stated first, but the final 'Routing:' section largely duplicates the main paragraph ('use over get_financial_summary for current numbers' appears twice). The redundancy adds no new information and could be trimmed to a single statement.

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 no output schema and moderate complexity, the description adequately covers what the tool returns (a set of named reports), when to use it, and the data source. The from_date/to_date scoping is supplied by the schema, and the safety profile is covered by annotations. Minor gap: it doesn't describe the return format of the report, but this does not block correct invocation.

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 the schema already documents kind, to_date, companyId, and from_date including defaults. The description adds marginal value by naming the report kinds, which mirror the enum, and by signaling the live-ledger nature. This is baseline-plus but does not materially expand on schema semantics.

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 ('Get a LIVE financial report straight from the company's connected Xero ledger') and enumerates the concrete report kinds (ProfitAndLoss, BalanceSheet, BankSummary, TrialBalance, ExecutiveSummary). It clearly distinguishes itself from the sibling get_financial_summary by positioning itself as the live-books source of truth.

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 choose this tool over the alternative: 'prefer this over get_financial_summary (which reads the periodically-processed snapshot) when the user asks about current/live financial position.' The routing section reinforces this with a clear conditional, which is exactly the guidance an agent needs to disambiguate from the sibling.

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