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

Annotations already establish this is a safe read of a closed scope, so the bar is lower. The description adds genuinely non-obvious behavior: returned third-party text is wrapped in 'untrusted_content' with a '_notice' and must be treated as data, not instructions — important prompt-injection context the annotations cannot convey.

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 sentences, both load-bearing: the first defines the payload, the second carries the safety caveat. Front-loaded and free of filler, though the second sentence is dense and could be slightly tighter.

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 no-arg, read-only, output-schema-less tool, the description covers what comes back (question plus public answers) and the critical trust boundary for that content. What remains unspecified — exact return shape — is minor at this complexity.

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?

The tool takes zero parameters, which is the baseline 4 case; there is nothing for the description to disambiguate beyond what the empty schema shows.

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 resource (today's question and its public answers) with a clear read intent, and routes the agent relative to siblings by noting it is 'the usual first step after join'. It doesn't explicitly name daily_answer as the follow-up action, so differentiation from that sibling is only implied.

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?

The parenthetical 'the usual first step after join' gives concrete sequencing context that tells an agent when in the workflow to call this. It stops short of explicitly naming the follow-up tool (daily_answer) or stating exclusions, but the entry-point role is clear.

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