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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description reinforces this with 'Only READS' plus the downstream 'apply the result with apply_schedule'. It also discloses graceful-degradation behavior (missing coordinates cause a refusal message). It does not cover result size, performance, or whether the plan is deterministic.

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-loads the core action and scope, then immediately covers prerequisites, fallback, and safety in three dense clauses. Every sentence carries information an agent needs to select and call the tool; there is no 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?

With no output schema, the description compensates by summarizing the return payload (assignment/order, suggested start times, km and drive minutes). Combined with the coordinate prerequisite, the fallback tool, and the read-only/apply split, an agent has everything needed to invoke and act on it.

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%: date format (YYYY-MM-DD), the technician filter with its default, and service_minutes with its default are all documented in the schema. The description adds only loose context (road routing, per-visit start times) and no parameter-specific syntax beyond what the schema provides, 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?

Names a specific verb (plan) and resource (one day's routes) and enumerates concretely what is produced: assignment of technician to job, visit order, suggested start times, and per-tech km/drive minutes. It is clearly distinguishable from siblings like plan_job_distribution and technician_route.

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?

Explicitly states the precondition (job coordinates required), what happens when it can't be met ('if none have them it says so'), and names the fallback sibling plan_job_distribution. It also closes the loop with the follow-up action apply_schedule, so the agent knows this tool is read-only planning.

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