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

Annotations only say destructiveHint=true; the description adds genuinely non-obvious behavior: the aggressive side effect on the task cover image and the fact that omitting confirm yields a non-mutating preview. That is exactly the extra context annotations cannot carry.

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 compact sentences, with the core destructive action front-loaded and the confirm requirement trailing. The parenthetical about the cover image earns its place as it prevents surprise data loss.

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 two-parameter destructive tool with no output schema and annotations covering the safety profile, the description supplies the essential missing pieces (preview gate, side effect). Minor gaps remain around permissions and reversibility, but nothing blocks correct invocation.

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 50%: 'confirm' is already fully documented in the schema, so the description's restatement adds little, while 'attachmentId' has no schema description and gets no format/ID guidance here either. Partial compensation only.

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 (an attachment from a task), and goes further by disclosing a secondary effect: removal of the task cover if the attachment was the cover image. This is unmistakably distinct from the nearby rename_attachment and add_attachment siblings.

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 description implies a two-step preview-then-confirm workflow via 'Needs confirm: true', which is usable guidance, but it never states when to choose this tool over alternatives or what preconditions exist (e.g., permissions). Usage is implied rather than spelled out.

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