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

Annotations already declare destructiveHint=false, idempotentHint=true, and openWorldHint=false, so the safety profile is partly covered. The description adds a genuinely useful fact beyond the annotations — 'Nothing on Google changes' — clarifying the discard is confined to the local draft and has no live-profile side effect. It omits whether the discarded draft is irrecoverable, which is the main remaining behavioral unknown.

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 action is front-loaded and the scope clarification follows immediately. Nothing to trim.

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 one-parameter tool with full schema coverage and annotations, the description is nearly sufficient: it says what happens and that nothing changes on Google. It would be complete with a note on whether discarding is reversible and how it differs from undo_change.

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% for the single change_id parameter, and the schema already explains it comes from a propose_ tool or my_changes. The description adds nothing further about the parameter, so 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 ('throw away') and resource ('a pending draft'), and clarifies the draft is one the owner does not want. It is distinguishable from sibling propose_*/publish_change tools, but it never contrasts itself with undo_change, the closest sibling and the most likely source of confusion.

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?

Usage is only implied: the phrase 'the owner does not want' suggests discard applies to unwanted pending drafts, but there is no explicit when-to-use statement, no prerequisites, and no pointer to undo_change for changes that were already published.

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