Update Card

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

Beyond the annotations, the description and schema disclose important behaviors: updates are partial, provided fields replace rather than merge, tags/assignees/descriptions/column are fully replaced, and due_on can be nulled. The assignee note even explains the five-assignee rejection and the read-back check. There is no contradiction with readOnlyHint=false or destructiveHint=false.

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 tool description is two short sentences that front-load the action, scope, and the crucial partial-update behavior. It is efficient and contains no 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?

The definition is largely complete: required parameters are declared, all optional parameters explain omission semantics, and replacement warnings are present. There is no output schema, but the assignee description compensates by describing the read-back behavior. A brief note about the response format would make it fully complete, but it is not essential for correct invocation.

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. The tool description adds a general 'only provided fields will be changed' rule, but each property already says 'omit to keep current,' so the description doesn't provide meaning beyond the schema. Per-parameter details like null due_on, empty assignee arrays, and replacement semantics are already in 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 clearly states the tool updates an existing card and lists the editable properties, which is more specific than just repeating the name. However, it does not explicitly distinguish itself from sibling tools like fizzy_move_card_to_column or fizzy_toggle_card_tag, so it falls just short of full differentiation.

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 top-level description itself gives no when-to-use guidance, but the input schema property notes explicitly route users to fizzy_close_card and fizzy_reopen_card for archiving workflows, to fizzy_toggle_card_tag for individual tag changes, and to fizzy_toggle_card_assignment for individual assignment changes. This is strong contextual guidance, though it doesn't mention fizzy_move_card_to_column as an alternative for column placement.

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