set_preferences

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

With no annotations, the description carries the burden and does well by disclosing that the tool replaces the whole layer and that {} clears it. It does not mention permissions, validation, or return behavior, which keeps it from a 5.

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 compact and front-loaded, with the core behavior and replacement semantics stated immediately. The example earns its place by clarifying the facets shape without wasting space.

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 mutation tool with no annotations, no output schema, and a nested object parameter, the description covers the essential behavior and both parameters. It stops short of describing return values or error conditions, which 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 description coverage is 0%, so the description must compensate. It explains project_id's layer precedence and provides an example structure for facets, though the arbitrary nested facets object remains only partially specified.

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 uses a specific verb and resource: 'Store standing facets applied to every route,' and clarifies scope with examples. It distinguishes this from per-task facets, though it does not explicitly name sibling tools like get_preferences or prefer_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?

Usage is implied by the scope ('standing facets applied to every route') and the exclusion of per-task facets, which go on the item instead. However, it does not explicitly name alternatives or say when to use this versus get_preferences or prefer_tool.

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