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

Beyond annotations that already mark it read-only, idempotent, non-destructive, and closed-world, the description adds useful behavior: a hard cap of 250 stripped rows, no writes to Xero, and permission/Reports-access prerequisites. The term 'stripped' is not defined and truncation behavior beyond the cap is not explained, so it is strong but not exhaustive.

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?

Three tight sentences, front-loading purpose before limits and permissions, with no filler. The wording is compact and scannable.

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?

It covers safety, access requirements, row cap, and report scope, and an output schema exists so return values need not be described. However, for a tool with five parameters and only 20% schema coverage, the unresolved meaning of date/from_date/to_date leaves a material invocation gap.

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 only 20%: workspace_id is documented, but report, date, from_date, and to_date are not. The description names the three report types and says 'explicit dates,' yet does not explain whether date, from_date, and to_date are alternatives, how they interact, or which report types require which date fields.

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 opens with a specific verb ('Read'), a precise resource ('one live Xero Profit and Loss, Balance Sheet or Trial Balance'), and scope ('for explicit dates'). This clearly separates it from sibling contact, invoice, workspace, and credit-control tools without needing their schemas.

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?

It implies use when a live financial statement is needed for explicit dates, but never explicitly states when to use this versus other reporting tools or when not to use it. No sibling alternative for financial reports is named, so the agent must infer the boundary from the resource name.

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