Update Issue

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

The annotations already indicate it's a non-read-only, idempotent, non-destructive operation. The description adds the partial-patch behavior and automatic version handling, which are meaningful behavioral traits not present in annotations. It does not contradict the annotations.

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 two sentences, front-loading the primary purpose and immediately adding the patch nuance and version warning. Every phrase carries information with no 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?

The description covers the core update behavior, patch semantics, and a critical concurrency caveat. Since there's no output schema, it doesn't explain the return value, but the annotations provide safety context. Given the tool's moderate complexity, this is largely sufficient, though additional parameter clarification would improve completeness.

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 low (only 3 of 11 parameters have descriptions). The description's partial-patch guidance adds a general semantic but does not explain individual parameters like type, status, or milestone, leaving ambiguity about expected value formats. This does not compensate sufficiently for the low schema coverage.

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 'Update an existing issue' with a clear verb and resource, and the parenthetical 'partial patch' distinguishes it from issue_create and issue_delete. It clearly identifies the tool's function among siblings.

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 guidance to only include fields to change, establishing the tool's partial-patch usage pattern. It also explicitly warns not to pass the version field due to automatic handling, giving a concrete exclusion. However, it doesn't explicitly contrast with issue_create, though 'existing issue' implies it.

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