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

With no annotations, the description carries the full disclosure burden, and it does surface a genuinely non-obvious behavioral trait: property stats are capped at the newest 5000 entities and the `sample_capped` flag signals truncation. That is exactly the kind of caveat an agent needs before treating fill rates as exhaustive. It does not mention permissions, but for a stats read that is a minor omission.

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: the primary capability is front-loaded and the sampling caveat follows. No filler, no restatement of the name.

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?

An output schema exists, so return values need not be explained, and the description covers both modes plus the sampling limitation. The only gap is the absence of any guidance about when to reach for this tool versus its many ontology/entity siblings.

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% and the `kind` parameter description already explains omit-for-all-kinds versus set-for-per-property-fill-rates, so the schema does the heavy lifting. The description's 5000-entity sampling note adds relevant context, but it does not add parameter-level detail beyond the schema, so 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?

States a specific verb (stats) and resource (object kinds), and distinguishes the two modes: per-kind counts/trends versus a single kind's property fill rates. It does not explicitly differentiate itself from nearby read tools like memory_ontology_list or object_search, so it stops short of a 5.

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 implies two usage modes and the schema spells out omit-vs-set for `kind`, but neither text states when an agent should prefer this over siblings (e.g. memory_ontology_list or memory_entity_view). Usage is inferable rather than guided.

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