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

Annotations already declare the write, idempotent, and non-destructive profile, and the description adds genuinely new behavioural context: the ask-by change applies only to Chases started afterwards, running Chases keep their existing checklist, and the tool returns a before → after diff. The main gap is that it never states the partial-update contract (omitted fields unchanged) or any permission requirement.

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?

Content is dense and front-loaded, with the effect surface first and a separate 'Use this when:' sentence for routing; every clause carries information. The drawback is presentation: eight field behaviours are packed into one very long run-on sentence, which is harder to scan than a short list.

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 9-parameter, zero-required mutation tool with no output schema, the description covers most of what an agent needs, including a hint at the return value ('before → after') and the forward-looking scope of changes. It is not fully complete: partial-update semantics and validation-failure behaviour are unstated, which matters when all parameters are optional.

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?

With only 56% schema description coverage, the description does real work: it explains that name and phone are Client-visible, that phone can be cleared, the 0–30 range with default 10 for ask_by_days, the 30–365 range for retention_days, and the 1–8 item limit for default_checklist. It does not clarify the semantics of sign_off, reply_to_email, or daily_summary beyond naming them, and leaves idempotency to the schema.

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 opens with a specific verb ('Changes') and then enumerates the exact resources and behaviours affected: client-visible name, reply-to email, sign-off, phone, ask-by days, retention days, daily summary, and default checklist. An agent can distinguish this from update_client (single client) and set_nudge_plan (nudges) without opening the 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?

The explicit 'Use this when:' clause gives concrete triggers (practitioner changes their details, the send-by date, default checklist, or retention), which is stronger than implied usage. It stops short of naming exclusions or alternatives, e.g. that per-client changes belong to update_client or nudge cadence to set_nudge_plan.

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