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

With readOnlyHint=true the safety profile is already covered. The description adds real behavioral value by stating filters combine with AND and that pagination uses next_page passed as page, but it never says the reply actually contains next_page or what the payload looks like, leaving the pagination loop half-described.

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 short sentences, front-loaded with the purpose before the filtering and paging mechanics. The trailing 'GET /main/Invoice' endpoint is slightly gratuitous for an agent but costs little.

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 14-parameter, zero-required list tool with no output schema, the description covers filtering and paging but omits the response shape (items vs. 'included' array, presence of next_page). The 'include'/'include_iterate' expansion behavior is only explained in the schema, not in prose.

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 all 14 parameters are already documented in the schema; baseline is 3. The description adds only the next_page-to-page mapping, which is a convenience pointer rather than new parameter semantics.

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 ('List or search invoices') plus scope ('of the practice group'), which distinguishes it from the singular halaxy_get_invoice. It does not explicitly separate itself from halaxy_list_invoice_lines, but the resource noun makes the boundary inferable.

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?

Usage is implied by the filter list and the 'Paged' note, so an agent can infer search vs. paginate flows. However, there is no explicit guidance on when to prefer this over halaxy_get_invoice or halaxy_list_invoice_lines, and no prerequisite information.

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