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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds the missing operational trait that matters here: the result set is paginated and the agent should 'paginate until hasMore=false'. It doesn't say what a page contains, but the output schema covers that.

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 tight sentences: what it finds, when to use it, how to consume the results. No filler and the identifying constraint (exact field keys) is front-loaded.

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, the description needn't explain return values, and it correctly spends its words on the pagination loop instead. The only gap is what 'enqueue research' operationally entails and that unmatched keys are presumably dropped.

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 0%, so the description must compensate and only partly does: it establishes that fieldKeys are exact-match and that offset/limit drive pagination via hasMore. It never mentions the 20-key array cap, the 100 default page size, or that keys are case-sensitive, leaving bounds to the schema.

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 ('Find saved field IDs across locations') and narrows the lookup to 'exact field keys', which separates it from the broad list_location_fields and the inverse find_locations_by_field. The sibling distinction is implied rather than named outright, keeping it 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?

'Use after bulk creation to enqueue research' gives a concrete triggering context, which is more than most definitions offer. It stops short of naming the alternative tool (e.g. list_location_fields) for agents who don't have freshly created keys.

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