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

Annotations already declare destructiveHint=true and idempotentHint=false, so safety and repeat-call behavior are covered structurally. The description reinforces this with 'this can't be undone' and clarifies the side effect that no time entry is created, but adds no other behavioral context such as whether a discarded stopwatch can be recovered or what state remains.

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, front-loaded with the action and immediately followed by the irreversible consequence. No wasted words.

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-parameter deletion with full annotation coverage and no output schema, the description gives the agent everything needed to call it correctly. Only marginal gaps remain around recovery or post-deletion state.

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?

Single parameter with 100% schema description coverage ('From list_stopwatches'), so the schema already tells the agent where to obtain the ID. The description adds nothing further about parameter meaning; baseline 3 applies.

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 (deletes) and resource (user's stopwatch) and adds a distinguishing qualifier, 'without booking its time', which separates it from book_stopwatch. It never names that sibling explicitly, so 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?

The phrase 'without booking its time' hints that the alternative is book_stopwatch, but the description never says when to choose discard versus booking or versus delete_time_entry. Usage is implied, not guided.

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