update_prefs

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

The description adds no meaningful behavioral detail beyond annotations. The 'retrieve or set' wording is confusing, and it does not state what gets updated, the scope of the preferences, or the effect of passing null.

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 text is very short and front-loaded, but the Args block is confusing and does not earn its place. It is concise but imprecise, and the 'retrieve or set' phrase actively undermines clarity.

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?

For a one-parameter tool with 0% schema description coverage, the description fails to explain how to pass preferences or what the data shape should be. It also does not say what scoping the preferences apply to, even though sibling tools and list_prefs/list_prefs_get exist.

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 0%, so the description is solely responsible for explaining the parameter. It calls prefs 'the preference key', but the schema expects an object (or null), not a key. It does not describe the key-value map structure, valid values, or default/null behavior.

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?

'Set preferences' is almost a direct restatement of the tool name, and the Args line says the prefs value is a 'key to retrieve or set', making it unclear whether this is a read or write operation. It gives no differentiation from sibling get/list preference tools or section-specific preference tools.

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?

There is no guidance on when to call this tool instead of list_prefs, list_prefs_get, or the section-scoped preference tools. The description fails to provide any context, prerequisites, or exclusions.

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