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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false) and openness, so the description's added value is the disclosure that it returns the most recent published observations with months, units, source and retrieval time, and that 'values may be revised.' That revision caveat meaningfully explains why idempotentHint is false, which the annotation alone does not.

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 two sentences are well-formed and front-loaded with the purpose and return behavior. The trailing logistics fragments ('Put tool fields inside inputs... Follow its required fields and exact choices... Do not pass the REST calculator field inside MCP arguments') are choppy, context-dependent, and reference an unexplained REST/MCP distinction that adds noise more than clarity.

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?

An output schema exists, so return-value explanation is optional, and the description does state scope and revision behavior. However, the nested `inputs` wrapper and the empty-property `units` object are only obliquely addressed, and the final REST-field warning is ambiguous enough that an agent could misconstruct arguments — a real gap for a nested-schema tool.

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 only 33%, and the description's parameter guidance is cryptic rather than clarifying: 'Put tool fields inside inputs' does hint at the nested wrapper object, but 'Supply units or modelVersion only when listed in inputSchema' is confusing given that `units` is an empty object with no declared properties. The `inputs.series` enum is already fully described in the schema, so little genuine meaning is added.

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?

The description opens with a specific verb and resource: 'Retrieve one supported monthly BLS series,' then enumerates the three valid series (CPI, construction-input PPI, private-sector earnings). It also fences the scope negatively ('not local wages or supplier prices'), which helps separate it from the market-price and earnings-adjacent siblings, though it never names an alternative data-lookup tool directly.

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?

There is a partial when-not-to-use signal ('not local wages or supplier prices') and a pointer to buscalc_business_data_calculations, but the routing sentence is vague: 'Use a separate business-data-calculations call with explicitly selected values' does not state the condition under which an agent should switch tools. Usage is implied rather than explicitly framed as when/when-not.

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