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

Annotations already declare readOnly/openWorld/non-destructive, so safety is covered. The description adds real context beyond that: access scoping ('only people your location access covers, admins: everyone') and the crucial staleness caveat that a position is just where the phone last reported. It stops short of describing latency or how road distance is computed.

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 sentences, no filler, with the core scope ('closest to a place by road') front-loaded. The final sentence compresses two distinct ideas (position provenance and the schedule-check caution) behind an em dash, which is slightly dense but still earns its place.

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 naming the returned fields (drive minutes, km, position age) and the result cap. Together with the permission-scope note, an agent has everything needed to call and interpret this tool 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%, so lat/lng-vs-address, limit range, user_ids, and within_hours bounds are fully documented in the schema. The description reinforces 'up to 5' and implies recency via 'how old the position is' but adds no syntax or format detail beyond structured fields, so the 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+resource with scope: technicians nearest a place by road, drawn from each person's latest reported position, capped at 5. The return fields (drive minutes, km, position age) make it distinguishable from find_technicians, technician_locations, and technician_route without opening any 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?

It implies dispatch/assignment usage via 'check their schedule before assigning work', which is a freshness caveat more than a routing rule. It never names an alternative tool or the condition that would select one (e.g. drive_time, find_technicians, technician_route), so an agent must infer when this is the right pick.

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