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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: what fields the response carries, that XSD validation results and databox delivery receipts are included only for submitted filings, and that includeXml enlarges the response with the full XML.

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?

A single dense sentence that front-loads the resource and then enumerates the return contents, with the includeXml note last. Every clause carries information; the enumerated field list is long but each item is meaningful for decoding the response, given there is no output schema.

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 carries the full burden of explaining return values and does so exhaustively — status, validation, summary sections, addressee, reviewer/timestamp, and conditional databox delivery fields. Nothing an agent needs to call or interpret the result is missing.

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 coverage is 100%, so both parameters are already documented; baseline would be 3. The description adds value by clarifying the provenance of 'id' (from list_vat_filings or generate_vat_filing) and noting that includeXml injects the complete XML into the response rather than just a fragment.

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+resource (detail of one generated VAT filing) and enumerates the concrete payload: status, XSD validation result, summary, addressee, review metadata, databox delivery status. It also names the sibling tools that produce the id (list_vat_filings, generate_vat_filing), so an agent can place it in the workflow without opening a schema.

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 says the id comes from list_vat_filings or generate_vat_filing, which tells the agent when this tool is the right next step. It does not state exclusions (e.g., use list_vat_filings instead when you only need the overview), so it stops short of full alternative routing.

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