update_issue

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

Annotations already provide safety hints (readOnlyHint false, destructiveHint false, idempotentHint true). The description adds valuable behavior beyond that: it states the tool returns previous values for rollback and explains the empty-parameter semantics ('empty = keep' or 'empty = skip'), which is meaningful for an agent. It falls just short of full transparency by not addressing error cases or required permissions.

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 one-sentence purpose and then uses a clear, consistent Args list. Every line adds semantic value; there is no fluff or repetition. The structure makes parameter semantics easy to parse.

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?

Despite having 10 parameters and no schema descriptions, the description covers the purpose, all parameter semantics, return behavior (previous values for rollback), and empty-value conventions. An output schema exists to describe return structure, so the description is complete enough for correct 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 0%, so the description carries the full burden. It compensates excellently by explaining each parameter's meaning and the special empty behavior for every optional field, plus providing a concrete command example. This level of detail lets an agent construct calls correctly without needing hidden knowledge.

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 fields of a YouTrack issue' with a specific verb and resource, and enumerates which fields are updatable. It does not explicitly distinguish from sibling tools like transition_issue or update_work_item, but the focus on issue fields is reasonably clear.

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 for use is implied by 'Update fields of a YouTrack issue' — an agent can infer it is for modifying issue attributes. However, there is no explicit when-to-use vs alternatives, no exclusions, and no mention of using transition_issue for state workflows, leaving some selection ambiguity.

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