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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds meaningful behavior on top: tenant-scoped refusal with NOT_FOUND for out-of-tenant ids, and the shape of the returned payload including portal_routes. It does not cover format or size limits of the returned sheet, keeping this from a 5.

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?

Front-loads the core action and return payload before routing hints, and every sentence carries information. Some sentences are dense and the 'Simpler never submits to LHDN' aside is a bit compressed, but overall it is efficient.

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?

There is no output schema, so the description carries the burden of explaining return values, and it does: it describes portal_field_sheet contents (details, supplier, buyer, lines, totals, coded values) and portal_routes. Combined with the NOT_FOUND behavior and NEXT-step routing, an agent has what it needs to call correctly.

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?

With 100% schema coverage and a single 'id' parameter, the baseline is 3; the description adds value by implying tenant scoping (an id outside your tenant yields NOT_FOUND) and pointing to myinvois_invoice_list as the source of valid ids, which is meaning beyond the schema's bare 'The myinvois_invoice id.'

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 ('Read one sealed e-invoice by id') and immediately characterizes the distinctive return payload (portal_field_sheet laid out for the LHDN MyInvois portal form). This clearly separates it from sibling read/list/search tools like myinvois_invoice_list and myinvois_invoice_search.

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 routes the agent: call myinvois_invoice_list for valid ids when an id is rejected, and follow with myinvois_invoice_record_submission using the UUID the portal assigns. It gives strong workflow context but does not explicitly contrast against myinvois_invoice_search as an alternative id-lookup path.

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