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

Annotations only give readOnlyHint and openWorldHint=false, so the description must carry the behavioral load, and it does add real value: it discloses that service_method drives the section 437c rows and the 998 offer deadline, and it openly flags the legal-basis caveat that no published decision applies sections 1013(c)/1010.6 to a 998 offer, so the tool follows Lecuyer v. Sunset Trails. That is genuine transparency beyond 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?

Two sentences, front-loaded on the core computation with the optional county extension held to the second sentence. The enumeration is dense but each item is a distinct returned deadline, so it earns its space; only the trailing 'this site tracks' aside is slightly loose.

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, the description carries the burden of telling the agent what comes back, and it does so by listing every computed deadline category. Combined with the disclosed service-method caveat and the county scope limit, an agent has enough to invoke and interpret this tool correctly.

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 four parameters (trial_date, county, set_date, service_method) are already documented in the schema, including the enum and pattern constraints. The description restates the optional county local-rule behavior and the service-method effect but adds little syntax or format detail the schema lacks, making the baseline 3 appropriate.

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 a specific verb (work backward / countdown) and resource (California civil trial date to pretrial deadlines) and enumerates exactly which deadlines it returns: discovery cutoff, motion cutoff, expert exchange, expert discovery, last day to serve written discovery, and summary judgment dates. The 'civil' qualifier also naturally separates it from the sibling california_criminal_motion_deadlines.

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 trial-date anchor makes the usage context clear, and it notes the tool covers 'one of the counties this site tracks,' which hints at scope limits. However, it never states when to prefer this aggregated countdown over the focused siblings like california_motion_deadlines, california_summary_judgment_deadlines, or california_discovery_response_deadline, nor any when-not condition.

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