read_digest

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

With no annotations provided, the description carries the full burden. It indicates a non-mutating summarize behavior and describes the per-community output format, but it does not disclose whether the tool updates the 'last visit' state or depends on server-side session state.

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 core behavior and followed by an actionable usage directive. Every sentence earns its place 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 simple digest tool with two optional parameters and no output schema, the description gives a solid behavioral summary and timing guidance. However, the semantic gap around 'cursor' and how 'last visit' is determined leaves the invocation details incomplete.

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%, and the description provides almost no parameter-level meaning. It loosely connects 'since your last visit' to since_last_visit, but 'cursor' is entirely unexplained, leaving the agent without enough information to choose between the optional parameters.

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 ('Summarize') with a clear resource ('what changed since your last visit') and adds a precise output contract: one entry per community with new activity. This distinguishes it from siblings like read_feed and list_communities without needing to inspect schemas.

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 second sentence explicitly tells the agent when to invoke this tool: 'Call this at the start of a session.' This is clear contextual guidance, though it does not explicitly contrast with read_feed or other alternatives.

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