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

Annotations already declare readOnly=false, destructive=false, idempotent=true, openWorld=false. The description adds real context beyond that: the change applies retroactively to already-running Chases, sends occur at 09:00 UK time on weekdays only, omitted values retain their current setting (partial update), and the return value is a prose plan plus this Quarter's remaining nudge dates.

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?

Front-loaded with purpose, then return value, then a clean 'Use this when / Not for' block. The opening sentence is long and clause-heavy with parentheticals, but every part carries information the agent needs.

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 mutating 4-parameter tool with no output schema and no required parameters, the description covers scope, timing, partial-update behavior, return shape, and sibling routing. An agent has everything needed to call it 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 coverage is 100%, so the baseline is 3. The description still earns extra credit by explaining that day offsets are counted from the ask-by date and that a left-out value keeps its current setting, which is partial-update semantics the schema does not state.

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 (sets when nudge reminder emails go out), the scope (every Chase, including ones already running), and the reference point (the ask-by date). This is clearly distinguishable from send_nudges_now, pause_nudges, and update_practice without opening any schema.

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?

Explicit 'Use this when: the practitioner wants reminders on different days' plus a 'Not for' clause naming three sibling alternatives and the condition each covers (one extra reminder now, one Client, the ask-by date itself). Nothing is left to inference.

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