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

Annotations already declare readOnlyHint=true and destructiveHint=false, establishing a safe read. The description adds value by disclosing that download URLs are short-lived and may expire, and advises re-calling to refresh them—a behavioral trait not captured in annotations or schema. It does not contradict annotations.

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 sentences: the first states purpose and output, the second gives a practical usage tip. No filler, fully front-loaded, and every sentence earns its place. Ideal length for a simple list operation.

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?

With no output schema, the description compensates by listing the exact return fields. The single required parameter is fully covered by the schema, and the expiration behavior is disclosed. An agent has all necessary information to invoke this tool correctly and interpret results.

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?

The schema has 100% coverage on taskId with description 'The task whose attachments to list.' The tool description adds minor clarification by specifying 'standalone task,' but this is largely redundant with the tool name. Since the schema already documents the parameter fully, the description adds little semantic value beyond the baseline.

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 clearly states the action ('List'), the resource ('attachments'), and the scope ('on a standalone task'), and enumerates the returned fields (fileName, mimeType, size, download url). This distinguishes it from sibling tools like create_standalone_attachment and delete_standalone_attachment, and from other list tools focused on different entities.

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 the primary use case (fetching attachments for a standalone task) and provides a specific re-invocation condition ('Re-call this if a previously fetched url has expired'). However, it does not explicitly mention alternatives or when not to use this tool, though the resource-specific naming makes the distinction clear.

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