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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds real behavioral context beyond them: results carry payment details and the call also returns time totals for today/week/month/year, an extra output an agent would not predict. It omits ordering and truncation behavior (the limit schema note is not echoed here).

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 dense sentences, front-loaded with what is listed, followed by the notable secondary output. The 'Lawcus:' brand prefix is minor noise but nothing else is wasted.

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 9 optional parameters, no output schema, and no required filters, the description needs to carry the return-shape burden; it names payment details and time totals but says nothing about ordering, default limit, or what happens when no filters are supplied. Adequate to call correctly, but gaps remain for an agent reasoning about results.

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 only 44%, so the description has to compensate, and it largely does by enumerating the filter dimensions (date range, user, practice area, matter, client, invoiced state) that map to the undocumented *_id and is_invoiced parameters. It leaves out 'kind' and 'limit' semantics and does not say how the id filters combine, so it is not fully compensating.

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: lists billable activity covering time entries, expenses and flat fees, with payment details. An agent knows immediately what it returns. It stops short of differentiating from the overlapping siblings lawcus_list_time_entries and lawcus_list_expenses, which also surface subsets of this data.

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 only implied: the phrase 'with payment details' and the cross-kind coverage suggest this is the combined/aggregated view, but the description never says when to pick it over lawcus_list_time_entries or lawcus_list_expenses, nor any prerequisite (e.g. invoiced vs uninvoiced use cases). No exclusions are stated.

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