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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds the meaningful scoping rule (excludes jobs that already have invoices, restricts to billable completed/closed jobs), but says nothing about return shape, row counts, or pagination 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, and the core definition is front-loaded before the usage examples. Every clause carries information.

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 parameters, no output schema, and annotations covering read safety, the definition supplies what an agent needs to select and call it. The only missing piece is the boundary against the near-identical sibling unbilled_jobs_for_tech, which matters given the crowded sibling list.

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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. It correctly implies a no-argument, workspace-wide sweep rather than a filtered query.

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 resource set ('completed/closed billable jobs that have NO invoice yet') with an explicit filter and a parenthetical gloss ('ready-to-invoice candidates'). This is a clear verb+resource definition an agent can distinguish from the similarly named sibling unbilled_jobs_for_tech.

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?

Provides concrete triggering intents ('what can we invoice', 'unbilled jobs'), which is unusually helpful for routing. However, it never states when to prefer a sibling such as unbilled_jobs_for_tech or find_invoices, so alternatives and exclusions are left to inference.

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