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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint, fully covering the safety profile. The description adds useful context: the data is time-bounded to today and 'mix' is a count rather than a ratio or object. However, 'Headge has no house view' adds a cryptic caveat without explanation, detracting from behavioral clarity.

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?

Three short sentences with the key categories front-loaded, so it is appropriately sized. However, the final sentence 'Headge has no house view' does not earn its place—it is unexplained jargon that raises questions rather than resolving them, so not every sentence is justified.

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?

With an output schema present and zero parameters, the description does not need to cover return values or argument semantics. It is adequate for a simple read tool but lacks usage context (when to call it) and leaves the 'Headge' caveat unresolved, which is a noticeable gap given quick sibling navigation would be helped by a usage pointer.

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 has zero parameters, so the schema needs no description, and the baseline is 4. The description's clarification that 'Mix is a count' addresses output semantics rather than parameters, which is acceptable since there is an output schema to carry the return format.

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 states the resource (today's catch-up) and the categories it contains (mix by horizon, new views, flips, divergence), going beyond the name. However, it reads as output content rather than a clear purpose statement, and the jargon sentence 'Headge has no house view' is unexplained and obscures the tool's function. It does not distinguish this from siblings like get_latest or get_view.

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?

No guidance on when to use this tool versus the siblings (get_latest, get_view, get_topic, etc.). There is no mention of alternatives, exclusions, or the context in which a catch-up summary is preferred over a latest-items or view query.

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