Add an attachment to a work item

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

The annotations already indicate a mutating, non-idempotent operation, and the description adds useful behavioral context: it creates an AttachedFile relation, has a 130 MB simple-upload limit, and produces a new work item revision. It does not address auth prerequisites or duplicate-file-name behavior, but it goes beyond what the annotations convey.

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 tightly written sentences front-load the core action and then add the relation, upload limit, and return values. No filler or redundant wording.

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 straightforward upload tool with full schema coverage and an output schema, the description is nearly complete: it gives the mechanism, the size limit, and the key return values. It could be more complete with explicit guidance on when to use this tool versus its siblings and any authentication prerequisites, but those are not critical for 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 100%, so the schema already documents all five parameters. The description's upload-limit and return-value details are contextual rather than parameter-specific, so it does not add much semantic meaning about individual parameters; 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?

The description clearly states the action ('Upload a local file and attach it to a work item') and identifies the resulting relation ('adds an AttachedFile relation'). This specific verb+object+target makes it easy to distinguish from sibling tools such as list_attachments, delete_attachment, and download_attachment.

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 context of adding a new attachment is unambiguous, but the description does not explicitly enumerate the sibling alternatives or say when not to use this tool. It provides a clear use case and an operational limit, so the absence of an explicit exclusion is a minor gap.

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