upload_attachment

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

Annotations already declare readOnlyHint=false (write operation), destructiveHint=false, and idempotentHint=false. The description adds a valuable prerequisite: 'requires WRITE_ENABLED=true', which is authentication context not present in annotations. It does not disclose details like size limits or whether the attachment is appended vs. replaced, but the annotations cover the safety profile, so this is adequate.

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?

The description is a single, well-structured sentence that front-loads the primary action ('Upload a base64-encoded attachment to a ServiceNow record') and includes a necessary prerequisite in a parenthetical. There is no wasted wording or redundancy.

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 five required parameters and no output schema, the description explains the purpose, prerequisite, and typical use cases. It does not describe the return value or potential failure modes, but for a straightforward upload operation with complete schema and annotations, this is sufficient for an agent to invoke the tool correctly.

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 input schema has 100% coverage with descriptions for all five parameters. The tool description reinforces base64 encoding and gives examples of file types (screenshots, documents), which slightly adds meaning beyond the schema, but it does not provide substantial param-specific detail. The baseline of 3 applies because the schema already does the heavy lifting.

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 uses the specific verb 'Upload' with a clear resource ('a base64-encoded attachment to a ServiceNow record') and distinguishes it from sibling attachment tools (list_attachments, get_attachment_metadata, delete_attachment) by being the only tool that creates/uploads. The mention of 'base64-encoded' and the target record adds precision.

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?

Provides explicit context with 'Useful for adding files, screenshots, or documents to incidents, changes, etc.', which guides the agent on typical use cases. It does not explicitly name alternative tools or state when not to use it, but the family of attachment tools is clear, and the description implies this is the creation operation.

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