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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so the mutation/repeatability profile is covered. The description adds genuinely new behavior beyond that: the resulting tracked time is floored at zero. It does not say whether an over-removal errors or clamps, or what the response looks like, which keeps it below a 5.

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 short sentences with zero filler; the core action comes first and the operational constraint follows. Nothing is redundant with the title.

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 4-parameter mutation with no output schema, the description supplies purpose, trigger conditions, and the key domain constraint, while annotations cover safety. It leaves the failure mode for over-removal and the sign convention of 'minutes' for removal unstated.

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 enums are documented, so the schema carries parameter meaning; the baseline of 3 applies. The description only adds indirect semantics via the zero-floor rule, not per-parameter guidance.

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 pair (add/remove) and resource (tracked time on a task), and the phrase 'by hand' implicitly distinguishes it from the timer-based sibling control_task_timer and from the read-only get_task_time_history.

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?

It names two concrete situations that select this tool: logging work done without the timer, and correcting a mistake. It stops short of naming the timer tool explicitly as the alternative for timed work, so the routing is clear but not fully enumerated.

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