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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds the non-obvious point that filtering happens client-side after the API returns everything, and that the reply signals when results were cut by limit. It omits pagination/offset behavior and whether filtering is inclusive at the boundaries.

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 the resource identification first and the filtering/truncation constraint immediately after. Nothing is padded.

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 and a shallow five-parameter read tool, the description covers the main gotchas: client-side filtering and truncated replies. Only the undocumented user_id parameter keeps it from being fully self-sufficient.

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 60%; limit and the two date parameters are documented in the schema, but user_id has no description anywhere. The description adds the semantics of matter_id and date range (client-side filtering) but never explains user_id, leaving a genuine gap.

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?

Names the specific resource (time entries) and enumerates what each record carries (hours, rate, total, matter, invoiced status), which is more than the title restated. It does not, however, distinguish itself from the sibling lawcus_report_time_entries, so an agent must guess which of the two to pick for time-related questions.

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 API returns all entries; filter here by matter and date range' gives real context for when this tool is appropriate, and the limit note explains truncation. There is no explicit when-not guidance and no routing to the alternative reporting tool that clearly overlaps.

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