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

Annotations already establish readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context: the two return shapes (aggregated agencies vs. single agency) and the report format ('columns, column_types, rows'). It does not cover auth or rate limits, but those are secondary given the read-only flag.

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 sentences with zero filler. The core action is front-loaded, and the conditional behavior and output format are stated efficiently in the following sentences. Every sentence earns its place.

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 description must explain return values, and it does so precisely for both agency_id branches. The report shape is given explicitly and tied to a known convention ('as for the other reports'), making the tool self-sufficient for an agent to call and interpret the result.

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?

The input schema covers 100% of parameters and already describes agency_id's behavior (omit to get one report per agency). The description reinforces this and adds the output structure, but that is more about return values than parameter semantics. The marginal addition over the schema is modest, so the 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?

The description states a specific verb ('Generate'), a precise resource ('QuickBooks tax summary'), and the tax types (GST/HST, QST, VAT filing lines). This clearly distinguishes it from sibling tax tools like get_tax_agency, get_tax_payment, or search_tax_payments, which deal with individual entities rather than a filing-line summary report.

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 description gives usage context (for a period) and explains the agency_id conditional, but does not mention when to prefer this tool over sibling tax tools or provide any exclusions. There is no explicit alternative named, so an agent must infer the selection criteria from the tool name alone.

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