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

With no annotations, the description carries the full burden and does meaningful work: it discloses the authorization model, the visibility rule ("seen only by them and the owner or office"), and the implicit-shop-yard fallback. It does not say what happens if a start already exists (overwrite vs. reject), which is the main remaining behavioral gap for a write operation.

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, front-loaded with the action and immediately followed by the mode switch and the permission rule. Slightly dense phrasing ("or with no person_id the shop's yard, used when a worker has none") costs a re-read but nothing is wasted.

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?

For a 6-parameter mutation with an output schema and no annotations, the description covers purpose, authorization, visibility, and defaulting behavior. Only overwrite/conflict semantics are missing, and return values are handled by the output schema.

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 67% and the single most important gap, person_id (no description in schema), is explained here: omitting it targets the shop's yard. lat/lng/label/source are already documented in the schema, so the description adds value precisely where the schema does not.

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: saving a worker's daily start location, with an explicit alternate mode when person_id is absent (the shop's yard). It is clear what the tool does, but it never names or contrasts the sibling routes_setLocation, so an agent must infer the boundary from the sibling list alone.

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?

"used when a worker has none" gives a concrete triggering condition, and the role sentence ("Owner or office for anyone; a worker for themselves") tells the agent who may call it and for whom. It stops short of stating when to prefer routes_setLocation or when this call should be skipped.

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