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

Annotations already declare the tool as non-read-only, destructive, open-world, and non-idempotent, so the safety profile is covered. The description adds that the color bar can be cleared, which is a useful behavioral detail beyond the annotations, but it does not disclose permissions, reversibility, or side effects. No contradiction exists between the description ('colour or clear') and the annotations (destructive mutation).

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 description is a single, front-loaded sentence with no wasted words. It efficiently conveys the action and target without redundancy or filler.

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 three-parameter mutation tool with full schema coverage, annotations that cover safety, and no output schema, the description is nearly complete. It could mention that changes affect only the visual color bar (non-destructive to data), but that is a minor omission and not essential for correct invocation given the available structured fields.

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%, and each parameter is well documented in the schema itself. The description adds no new parameter-level meaning—it merely restates that clearing is possible, which the schema already specifies via the 'none' enum value. With the schema doing all the heavy lifting, the baseline score of 3 is 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?

The description states a specific verb ('Colour') and a concrete set of resources (the bar on top of a note, to-do list, link, file, or column), making the tool's effect clear. It does not explicitly differentiate from any sibling tool, but no sibling performs the same action, so the purpose is unambiguous.

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 description implies when to use the tool—whenever a card's color bar should be set or cleared—but offers no explicit conditions, exclusions, or alternative tools. A straightforward mutating tool like this has an obvious implied use case, yet the definition stops short of guiding the agent on when not to use it or how it relates to other color-related operations.

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