hyperfeed_digest

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

With no annotations, the description carries the transparency burden and does a good job disclosing behavioral details: personalization logic, ranking criteria, and the existence of a 'last-delivered watermark' that defaults when since is not provided. However, it doesn't explain whether the watermark is updated automatically after delivery or describe response format, which leaves minor ambiguity.

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 three sentences, each earning its place: the first defines what it is, the second tells when to call, the third explains parameters and follow-up. It is front-loaded and concise with no filler.

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 tool with no output schema, the description is fairly complete: it explains what the tool returns (news/releases/events), the usage protocol, and the related hyperfeed_react action. It doesn't detail the exact output structure, but the 'brief' wording implies a deliverable text, which is sufficient for an agent to act.

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 schema only provides the parameter name and type, but the description adds crucial meaning: since is an ISO-time filter, and if omitted, the last-delivered watermark is used. This fully covers the single parameter, compensating for the 0% schema description coverage.

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 tool's purpose: it delivers the user's personalized daily brief of high-relevance news/releases/events, ranked by recency, engagement, and interests. The verb 'call' and resource 'daily brief' are explicit, and it's distinct from siblings like hyperfeed_subscribe and hyperfeed_react.

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 description gives explicit when-to-use guidance: 'Call this each morning and deliver it.' It also explains parameter usage (pass since for new items, otherwise use watermark) and directs the agent to report engagement via hyperfeed_react, which is a clear reference to the follow-up action.

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