update_issue

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

With no annotations, the description should disclose behavioral traits like partial-vs-replace semantics, permission requirements, or side effects. The phrase 'Update fields' merely restates the tool's purpose and doesn't add any behavioral detail beyond the bare action.

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 consists of a single clear sentence that is directly to the point. No filler or unnecessary detail, earning a perfect score for conciseness.

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?

The schema fully documents parameters, so the description doesn't need to repeat them. However, for a mutation tool with no annotations and no output schema, the brief description leaves out important context like whether unspecified fields are preserved or overwritten, and what the return value indicates. This makes it adequate but not complete.

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 coverage is 100% with descriptive text for every parameter, including the 'labels' replaces-existing note and the customFields format example. The description adds nothing beyond the schema, so the baseline score of 3 is appropriate.

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 states a clear verb ('Update') and resource ('fields of an existing Jira issue'), specifying the action and target. It distinguishes from sibling tools like create_issue and update_issue_status by focusing on field updates, not creation or status changes.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention exclusions or prerequisites, nor does it reference sibling tools like create_issue or update_issue_status. The description is silent on usage context.

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