user_profile_get

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

Annotations already carry readOnlyHint=true and openWorldHint=false, and the description confirms rather than contradicts that. It adds real behavioral context beyond the annotations: only *currently-valid* facts are returned (superseded ones are excluded) and the rendered block is what gets injected into replies. No auth or rate-limit details, hence not 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?

Two short sentences, front-loaded with the resource and return content, with zero filler. The standalone 'Read-only.' sentence largely duplicates the readOnlyHint annotation, a minor redundancy that keeps it off a 5.

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 read tool with no output schema, the description covers what is returned, how it is scoped, and where the write alternative lives. Nothing an agent needs to call it correctly is missing.

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 user_id documented as a 'Stable per-user id from the channel', so the baseline is 3. The description only reinforces single-user scoping ('One user's') and adds no format or sourcing detail 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?

States a specific verb and resource (one user's currently-valid preference facts) and describes precisely what comes back, including the rendered '## About This User' block. It is unmistakably distinct from the sibling write tool user_profile_record, which it names.

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?

Explicitly routes mutation to the alternative: 'Add or change facts with user_profile_record.' Clear context for a read, but it doesn't spell out the trigger condition (e.g., before composing a reply to that user), leaving when-to-call slightly implied.

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