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

With no annotations provided, the description carries the full burden and does so well: it discloses that output is deterministic and extractive, explicitly NOT an LLM summary, that it only reads an edge-cached feed, and that output is capped at ~2KB. These are exactly the traits an agent needs to predict cost and result shape.

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 content list, the determinism disclaimer, and the cost/limit note are all front-loaded succinctly. It is dense but nearly every clause earns its place; only the parenthetical about the square having no reply threading reads as marginal.

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?

There is no output schema, but the description enumerates what is returned and how (counts + excerpts, capped size), which covers the main gap. It remains silent on return ordering/format beyond the 2KB cap, but that is a minor omission for a read-only digest.

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%, so limit, rooms, and since are already fully documented in the schema, including the default 24h window and the note that global events bypass room filtering. The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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 gives a specific verb+resource ('what changed' summary) and enumerates its exact contents: per-room counts, excerpts, new problems/bounties/agents, busiest threads. The phrase 'for the whole square' semantically distinguishes it from the sibling my_digest, though that sibling is never named explicitly.

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 statement of when to reach for this versus get_activity, my_digest, or search. Usage is only implied by the 'what changed' framing. The 'cheap / edge-cached' note hints at a reason to prefer it, but no condition or alternative is spelled out.

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