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

Annotations already flag destructiveHint=true, but the description adds substantial context beyond them: permanence, the authorization model (self vs project owner), the billed-time restriction, and the dry-run preview behavior when confirm is absent. This tells the agent exactly what gets destroyed and under what authority.

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 tight sentences, front-loaded with the irreversible action, then permissions, then the confirm requirement. No filler, and each clause carries distinct operational information.

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 destructive two-parameter tool with no output schema, it covers safety, authorization, and preview semantics well. It stops short on the shape of the preview result and the entryId format, which are the remaining gaps.

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 50%: confirm is fully documented in the schema and the description merely restates its preview semantics, while entryId has no description anywhere and its format is never clarified. It adds marginal meaning over the schema rather than compensating for the coverage gap.

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 precise verb and resource ('Permanently deletes a time entry, or a running timer'), and distinguishes the two object types this acts on. An agent can separate this from list_time_entries, update_time_entry, or stop_timer without opening any schema.

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?

Explicit conditions are given: a person may delete their own entries, a project owner may delete anyone's, and time already billed to a client cannot be deleted. It also states the mandatory confirm: true precondition and what happens without it, leaving nothing to inference.

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