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

Annotations already declare readOnlyHint=true, destructiveHint=false and closed-world, so the safety profile is covered. The description adds the notable behavioral fact 'rendered directly', telling the agent this returns a rendered chart rather than queryable records — valuable since there is no output schema. It does not cover chart size, format details, or empty-result behavior.

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?

Two tight sentences with zero filler. The chart type and scope lead, followed by the parameter contract and usage hint in order of importance.

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 one-parameter, read-only chart tool with annotations covering safety, the description supplies the parameter contract and output nature, which is what an agent needs to invoke it. Minor gaps remain around chart format/dimensions and behavior when there are no open jobs.

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% and the schema declares no enum, so the description does the real work: it enumerates the four accepted `by` values and states the default ('status'). That fully compensates for the schema gap for a single optional parameter.

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 ('Bar chart of') plus resource ('OPEN jobs') and the dimension being varied, so an agent can distinguish it from data-returning siblings like technician_jobs or revenue_by_month. The scope qualifier 'OPEN' is a meaningful constraint stated up front.

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 for quick visual breakdowns' implies a context but names no alternative and gives no when-not guidance, even though several siblings (activity_summary, ops_report) could plausibly serve similar reporting needs. Usage is implied rather than routed.

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