Update Workspace Variable

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

The description adds valuable behavioral details beyond annotations: partial-update semantics ('Omitted optional fields keep their current values') and output masking ('Returned values are masked when secret or sensitive'). These are not evident from annotations (readOnlyHint=false, etc.) and help the agent understand side effects and response characteristics.

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 concise (two sentences) with no redundant wording. It front-loads the core purpose and immediately adds the key behavioral notes. Every sentence earns its place.

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?

With 8 parameters and an output schema present, the description provides high-level behavior but leaves parameter details entirely to the schema. It covers partial update and masking, which are crucial, but does not mention required identifiers, permission prerequisites, or error scenarios. Given the tool's moderate complexity, it is minimally adequate but could be more 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 description coverage is 0% — the description does not mention any of the 8 parameters or their meanings. While the schema provides types and required flags, the description fails to clarify the role of fields like key, value, isSecret, isEnabled, or how variableId identifies the target. The description offers no additional insight beyond what the schema already shows.

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 ('Updates one workspace-global variable') and the resource ('workspace-global variable'), distinguishing it from sibling tools like create_variable and delete_variable. The mention of 'one' distinguishes it from batch operations like replace_variables, though not explicitly.

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 implies usage for updating a single workspace variable, but does not provide explicit guidance on when to use this tool versus siblings like replace_variables or create_variable. No exclusions or alternative recommendations are given.

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