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

Annotations already declare idempotentHint=true, destructiveHint=false, readOnlyHint=false, so the safety profile is covered. The description adds value beyond them by stating the clearing convention (null for dueAt/owner/description) and the immutability of the linked account/conversation, which an agent cannot infer from 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?

One dense sentence grouping the updatable fields plus one short constraint sentence. The key information is front-loaded and nothing is wasted, though the parenthetical clauses make the first sentence slightly long.

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 an output schema present and annotations covering safety, the description only needs to convey scope, field semantics, and limits, all of which it does. It stops short of noting permission requirements or conflict behavior, but nothing essential for calling the tool correctly is missing.

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 the baseline is 3, but the description adds real semantic detail beyond it: null explicitly clears dueAt, unassigns owner, and status 'done' sets completion as a side effect rather than being a plain field write.

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+resource ('Update a CRM follow-up task') and enumerates the mutable fields (title, description, dueAt, owner, status, priority), so an agent can distinguish it from create_crm_task, get_crm_task, and the generic update_task without opening a 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?

It gives an explicit exclusion with a remediation path ('Changing the linked account or conversation is not supported; create a new task instead') and scopes the tool to tasks 'you can work'. It does not, however, disambiguate from the sibling update_task, so the when-to-use guidance is strong but not complete.

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