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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses the multi-case digest behavior when matter_id is absent and explains that each entry carries the court's own wording to read and explain. These are meaningful behavioral traits not present in the annotations.

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?

The description is compact and front-loaded: the first sentence defines the core function, followed by usage examples, parameter-specific behavior, and result interpretation. Every sentence earns its place with no repetition or filler.

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 read-only tool with three optional parameters and no output schema, the description covers the key usage scenarios, digest behavior, and return-value interpretation ('court's own wording'). It does not describe pagination or sorting, but the schema covers limit, and the description is sufficiently complete for correct invocation.

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?

Even though schema coverage is 100%, the description adds practical semantics for `since` ('work out the date yourself') and `matter_id` (digest behavior for accounts with multiple vs. one case), which enriches the schema's dry parameter definitions.

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?

The description states a specific verb and resource: 'Return what is new in the user's connected cases' specifying docket entries and CaseMail since a given time. It clearly differentiates from siblings like get_recent_case_activity by emphasizing cross-case digests and the 'since' time filter.

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 description provides concrete example queries ('what changed', 'what happened this week') and instructs how to handle relative periods by computing the date and passing `since`. It clarifies behavior when matter_id is omitted, giving clear context for use, though it does not explicitly name alternative tools or exclusions.

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