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 context beyond annotations: data comes directly from HMRC MTD and HMRC MTD must be connected.

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 tightly worded sentences: the first states what is read and from where, the second gives usage triggers and the connection prerequisite. No filler or repetition.

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 read-only, three-parameter tool with full schema coverage and rich annotations, the description covers purpose, source, prerequisites, and triggering questions. It does not describe return shape, but the tool is simple enough and no output schema exists.

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 from, to, and company in detail, including date defaults and the yearly capping caveat. The description adds no parameter-specific meaning beyond the schema, so the baseline 3 applies.

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: reading VAT payments HMRC has received, directly from HMRC MTD. This clearly distinguishes it from sibling tools like get_hmrc_vat_liabilities, get_hmrc_vat_obligations, and get_vat_periods, which concern liabilities, obligations, or periods rather than received payments.

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?

Gives explicit user-question triggers ("has HMRC received my VAT payment", "what VAT have I paid") and a prerequisite ("Requires HMRC MTD connected"). It does not name alternatives or exclusions, but the usage context is clear.

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