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

With readOnlyHint=true already indicating a safe read operation, the description adds valuable behavioral context: weekly update cadence, historical depth to 1949, and the nature of the returned data (source lineage, methodology version). This goes well beyond the annotation's minimal safety signal.

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 description is three sentences and front-loaded with the core function. Every sentence adds value: what it returns, when to use it, and update frequency. No wasted words or redundancy.

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 simple indicator tool with one optional parameter and no output schema, the description covers the essential aspects: return contents, use cases, update frequency, and historical coverage. It lacks a sample output or any caveats about the 'days' parameter behavior, but the schema handles that parameter. Overall, it is complete for its simplicity.

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%, so the 'days' parameter is fully documented in the schema. The tool description does not add any additional parameter context, which aligns with the baseline score of 3 for high schema coverage; it neither helps nor hurts.

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 clearly specifies the tool's function: returning a 0-100 federal-spending momentum score with specific components (score, trend direction, source lineage, methodology version). The unique metric and data source (USAspending award and obligation flows) distinguish it from siblings, and the explicit use cases reinforce its specific purpose.

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 provides explicit context for when to call the tool, listing relevant user intents such as federal spending acceleration, budget momentum, and govcon bid/no-bid decisions. However, it does not mention any exclusions or explicitly name alternative tools, so it falls short of the 'explicit when/when-not/alternatives' bar.

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