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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the endpoint path and the semantic meaning of the returned groups, but says nothing about pagination, result size, or error behavior for an invalid client id.

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 compact sentences with zero filler; the resource is front-loaded and the endpoint reference trails as supporting detail. Nothing could be removed without losing information.

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 single-parameter read-only list tool with full schema coverage and annotations, this is nearly sufficient; the one gap is that with no output schema, the description does not indicate the shape of returned groups (e.g., ids/names of grouped jobs).

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% and the single parameter (client_id, with type and bounds) is fully documented there. The description only echoes the client scoping via the path template, adding no format or constraint detail beyond the schema — baseline 3.

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 the resource specifically ('contract invoice groups of one client') and adds a clarifying gloss — which jobs are invoiced together — that tells an agent what an invoice group actually is. It is distinguishable from the sibling list tools by resource, though the verb 'list' is only implied by the name/title rather than stated.

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 'of one client' phrasing implies the tool is scoped to a single client and that a client id is required, but there is no explicit when-to-use guidance or reference to alternatives (e.g., other client-scoped list tools or report tools). Usage is inferable rather than stated.

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