Set a profile field

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

The description adds minimal behavioral context beyond annotations. The annotations already declare idempotentHint=true and readOnlyHint=false. The description adds 'durable' and 'upsert', which imply persistence and idempotency but don't contradict annotations. No additional warning about side effects or auth needs.

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 a single, front-loaded sentence with no wasted words. It efficiently conveys the core action and scope.

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 simplicity (3 params, no enums, output schema exists), the description is minimally adequate. However, it misses context about how 'profile fact' relates to sibling tools that add specific records, leaving the agent to guess which tool to use.

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 100%, with clear explanations for 'key' (examples), 'user' (defaults to primary), and 'value' (free text). The description adds the context of 'durable profile fact' but does not improve parameter understanding 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 the action ('Set (upsert)') and the resource ('durable profile fact for a user'). It distinguishes from siblings like 'get_profile' and 'delete_profile', but does not explicitly differentiate from the many 'add_*' tools like 'add_allergy' or 'add_condition' that might also set facts.

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 use this tool versus alternatives like 'add_allergy' or 'add_condition'. The description only states what it does, not when it's appropriate 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.