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

With no annotations, the description carries the full load and does substantial work: it discloses the return envelope {items,total,offset,limit}, the fields per item, filter prefixes, sortable fields, and the non-obvious constraint that timestamps support only __gte/__lt (no bare equality). It omits auth/tenant-permission requirements and error behavior, so it is strong but not complete.

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?

Front-loaded with purpose and return shape, then progressively detailed syntax. The operator rules are dense but each sentence conveys a distinct constraint. It reads as one long block rather than segmented, which slightly hurts scannability, but there is little 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?

No output schema exists, and the description compensates by describing the response envelope and item fields. Given 6 optional parameters and nested fieldFilters, the filtering model is well-covered. Missing only operational context such as tenant scoping behavior by default and error/pagination edge cases.

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 coverage is 100% (baseline 3), but the description goes well beyond the schema, which only says 'see this tool's sort fields' and 'see this tool's filter prefixes.' It actually enumerates the sort fields, the filter prefixes (type:, name:, uuid:), the fieldFilters scope/score_scope values, and the full operator matrix with the timestamp exception — real added meaning.

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 and resource (list/filter Mallory observables) and immediately gives the concrete item shape (type, name/value, verdict/opinion counts), which distinguishes it from get*, which returns the full detail object. The final sentence explicitly hands off to getObservable, so an agent can route without opening a schema.

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?

Clear context for use (bulk listing with filtering/sorting/pagination) and an explicit alternative: 'Pass an item's identifier to getObservable for the full detail object.' It does not state when-not-to-use or mention permissions/prerequisites, so it falls short of 5, but the sibling routing is unambiguous.

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