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

Annotations already declare non-destructive, idempotent write behavior, so the bar is lower. The description adds genuinely useful behavioral context: a preview mode exists and changes are only applied when confirm is true, which is the key safety trait for this 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?

Two compact sentences with zero filler; the mutation action is stated first, followed by id provenance and the confirm rule. Every clause earns its place.

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 single-required-param mutation with no output schema, the description covers what changes, how to obtain the id, and the confirm safeguard. It does not describe what the preview returns, but with no output schema that is a minor omission.

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 baseline is 3. The description still adds value by naming the source tools for action_id and by explaining the preview/confirm interaction ('Preview first; confirm: true applies'), which the schema documents but the description reinforces in workflow terms.

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?

States a specific verb and resource ('Mark an action-plan item as done') and clarifies the resulting state ('same state as the dashboard Action plan'). It is clearly distinguishable from siblings like dismiss_action or delete_article.

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?

Tells the agent where the required id comes from ('Use the action id from get_action_plan or get_easiest_wins') and prescribes the workflow ('Preview first; confirm: true applies'). It does not address when not to use this tool versus dismiss_action, but the core context is explicit.

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