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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=false. The description usefully adds patch semantics — omitted fields are preserved — which qualifies the destructive flag and tells the agent old values are not wiped. It does not cover permissions, reversibility of a value change, or whether clearing a deadline is the only removal path, so it is additive but incomplete.

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?

Two sentences, zero filler, with the field scope front-loaded and the patch semantics as the immediately following qualifier. Nothing could be cut without losing meaning.

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 7-parameter mutation tool with no output schema, the description covers scope and the key patch behavior, and annotations carry the safety profile. It is nearly complete; the only real gap is that the clear_due_date removal path is never surfaced in prose, which is a plausible agent question given due_date is mentioned.

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 every parameter is already documented in the schema, which sets the baseline at 3. The description adds only a high-level field list and omits clear_due_date entirely, so it contributes no syntax or format detail (ISO-8601, priority enum) 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 names a specific verb (change) and resource (card) and enumerates the exact editable fields: title, description, priority, deadline. That field list implicitly separates it from siblings like move_kanban_card and set_kanban_assignee, but no sibling is named explicitly, which is what would push this to a 5.

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?

"Fields you leave out stay as they are — this is a patch, not a replacement" is a genuine calling guideline that tells the agent how to invoke it correctly. However, there is no when-to-use/when-not-to-use guidance and no mention of alternatives (get_kanban_card to read first, clear_due_date to unset). Usage is implied rather than directed.

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