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

Annotations already declare readOnlyHint=true, but the description adds useful context beyond that: 'Pure/offline' tells the agent there are no network side effects, and the return shape '{ count, total, events }' sets expectations. It doesn't discuss ordering or whether 'total' reflects the filtered or unfiltered catalog.

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 the resource and catalog contents, then filters, then the offline/return-shape note. Every clause contributes information and there is no repetition.

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 no output schema, the description still states the return shape and enumerates the catalog's fields. Filters, offline behavior and read-only safety are all covered, leaving nothing an agent needs in order to call it correctly.

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 both parameters are fully enumerated with descriptions, so the schema carries the parameter documentation. The description's 'Filter by category or platform' merely restates what those fields do, adding no extra semantics.

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 the canonical mosadd threat-event taxonomy') and enumerates the fields returned (id, category, default severity, auto-actions, per-platform availability). This clearly distinguishes it from the sibling threat_classify, which classifies events rather than listing the catalog.

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?

Says to use it 'to discover what the defensive engine recognises' and notes the two filter dimensions, giving clear context for when it is appropriate. It stops short of naming an explicit alternative or exclusion (e.g. 'do not use for classifying a live event, use threat_classify').

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