update_variable

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

The description goes well beyond annotations, detailing shallow merge behavior, null value handling, list replacement, concurrent edit detection via fingerprint, and that changes stay in draft until publishing. Annotations were minimal (readOnlyHint=false, destructiveHint=false), so the description adds significant value.

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 well-structured: a concise one-line summary, followed by a clear explanation of merge behavior, then an ordered Args list. Every sentence adds value without unnecessary verbosity.

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 the 5 required parameters and no schema descriptions, the description covers parameter semantics and output behavior (returns updated variable). It also notes draft persistence and concurrent edit safety. However, it could include error handling details or more on return structure, but overall it's fairly 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?

The input schema has 0% coverage (no descriptions), but the description's Args section explains each parameter, especially changes as a partial variable body with an example. While it doesn't fully enumerate allowed fields (since changes is flexible), it adds meaningful context 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 'Updates a variable by merging changes into its current config.' It specifies the verb (updates) and resource (variable), and distinguishes it from sibling tools like create_variable and delete_variable. The merge semantics are explained, making the purpose unambiguous.

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 is for modifying existing variables, and provides context like requiring variable_id from list_variables and workspace_id from list_workspaces. However, it does not explicitly state when to use this tool versus alternatives (e.g., create_variable for new variables) or when not to use it.

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