preferences_set

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

Annotations already declare this is a non-destructive, non-open-world write, so the safety profile is covered. The description adds nothing beyond that: no mention of whether changes persist across sessions, what happens on an unknown key, or whether values are coerced. For a mutation with 0% schema coverage, this is thin.

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?

One short sentence that front-loads the action and folds in the cross-reference. No wasted words.

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?

An output schema exists, so return values needn't be explained, and annotations cover the write semantics. What's missing is the shape of a valid key/value pair — the one thing an agent must get right to call this successfully — since the schema provides no hints.

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% and neither key nor value is documented in the schema, so the description does real work by routing the agent to preferences_get for valid keys. It says nothing about the value parameter's expected type or format, so the compensation is only partial.

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?

States a specific verb and resource: sets a single Toolbag application preference. It's clearly distinguishable from the sibling preferences_get (read vs write), though it doesn't say what kinds of preferences exist, leaving that to the referenced tool.

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?

Points the agent at preferences_get to discover valid keys, which is the main prerequisite for using this tool. It doesn't offer exclusions or say when a preference change is preferable to other setters (sky_set, render_set), but the usage context is clear.

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