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

Beyond the annotations, the description discloses two important behavioral traits: an empty value clears the field, and permissions differ by role (Administrator/ProjectManager vs. Member only on assigned tasks). It does not cover error handling for invalid values or response behavior, but it adds substantial operational context.

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 definition is two dense sentences with the core action and clearing behavior front-loaded, followed by value-type constraints and permissions. No sentence is wasted.

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 simple setter with full schema coverage and annotations, the description is largely complete: it covers scope, clearing, type requirements, and permissions. The only minor gap is that it does not mention what happens on invalid input or describe the response.

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 parameter basics are already documented. The description still adds meaningful semantics for the `value` parameter by mapping field types to expected formats (number, ISO date, boolean, select option, http(s) URL), which is useful domain guidance beyond 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 states a specific verb and resource with scope: 'Set one custom field on one task.' It also explains the clearing behavior, so an agent can immediately distinguish this from broader task updates or custom-field listing tools.

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 clear usage context by listing the acceptable value forms per field type and by spelling out role-based permissions. It does not explicitly name alternatives such as update_task for built-in fields, so it stops short of full when/when-not guidance.

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