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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true); the description adds real context beyond them by scoping which card operations are reachable here and by stating the return shape. It does not explain the semantics of the individual operations — notably whether 'pick' claims the card exclusively or what 'release' restores — which matters for a non-idempotent 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?

Three tight sentences, front-loaded with the core action and the operation list before the restriction boundary. The trailing 'Returns {ok, card}' is slight duplication given an output schema exists, but it costs almost nothing.

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 output schema makes the return explanation unnecessary, and the CLI-only restriction is well covered, but the description never explains what 'pick', 'done' or 'release' actually do to the board state. For a five-parameter, non-idempotent mutation tool, an agent still has to infer the core semantics of the operations from their names alone.

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 including 'nr', 'session' and the op enum is already documented in the schema. The description mirrors that mapping (update→note, done→proof) without adding syntax, constraints, or meaning for the opaque op values 'pick' and 'release'. Baseline 3 is appropriate when the schema carries the load.

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 gives a specific verb+resource ('Changes one card of the account task board') and enumerates the four allowed operations (pick, update, done, release), which lets an agent distinguish it from the sibling 'tasks' listing tool. It stops short of naming that sibling explicitly, so the differentiation is implied rather than stated.

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?

Provides an explicit when-not boundary: moving, renaming, assigning and discarding cards must go through the owner's voicehook-agent CLI with an agent key, not this tool. What is missing is a positive pointer to the read-side alternative (e.g. 'tasks' for listing/inspecting cards), so the routing guidance is one-sided.

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