update_issue

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

With no annotations, the description carries the full burden. It discloses partial-update behavior, 'leave alone' sentinels, that description replaces entirely, notes appending to history, and the inability to clear fields. This is comprehensive for a mutation tool.

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 opens with a clear one-sentence purpose, then systematically lists all 16 parameters with sentinel conventions. It is long but every part is informative, and the 'Leave alone' sentinels summary is a useful close. Slightly verbose but appropriately sized for the complexity.

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?

Given 16 parameters and no annotations, the description covers all parameter semantics, sentinel behavior, and limitations. An output schema exists for return values, so the description is sufficient for invocation. Minor gaps like error handling or permissions are not addressed but are not essential.

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 0%, and the description fully compensates by explaining every parameter, its sentinel value, and providing an example for custom_fields. This adds substantial meaning beyond the schema.

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 'Update an existing issue. Only changes the fields that are provided.' This specifies the action (update), resource (issue), and distinguishes it from create_issue, bulk_update_issues, and delete_issue.

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 provides clear context about partial updates and explicitly notes 'There is no way to clear a field through this tool — to blank out a date or remove an assignee, use the Redmine web UI.' However, it does not mention any sibling tools as alternatives, such as bulk_update_issues for multi-issue updates.

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