Get job costing

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

Annotations already cover the read-only, idempotent, non-destructive profile, yet the description still adds substantial interpretive context: what each cost bucket contains, that negative difference means over budget, that unpriced costs fall under Unassigned, that time card hours are priced via labor_rate, and that amounts are dollars. This is exactly the behavior an agent needs to interpret the numbers correctly.

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?

The first sentence front-loads the result shape, and the second packs the derivation rules. It is dense but every clause carries information; only the trailing 'Read only' repeats what the annotations already declare.

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?

There is no output schema, so the description must describe the returned fields, and it does: contract value, estimated, actual split, difference, and invoiced amount. For a 3-parameter aggregation tool this leaves no material gap.

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 100%, so the baseline is 3, but the description genuinely adds meaning: it clarifies that labor_rate prices time card hours and defaults to burden_rate, and that budget_from draws from the Schedule of Values or approved estimates plus change orders. That goes beyond the schema's terser wording.

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 and scope: estimated vs. actual cost per cost code for one project, with difference and totals. That is far more precise than the sibling list_cost_items or get_estimate, though it never names a sibling to contrast with explicitly.

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?

The description implies usage by identifying its source (the Job Cost Actual report) and its aggregate nature, so an agent can infer this is the reporting/roll-up tool rather than a line-item lister. However, it never says when to prefer it over list_cost_items, get_estimate, or get_change_order, and gives no prerequisites beyond the schema's project_id note.

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