nih_spending_by_category

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

Annotations provide readOnlyHint=true, and the description adds meaningful behavioral details: it 'Uses RCDC spending categories with an agency-based fallback for more accurate counts' and returns 'estimated funding', indicating approximate values. This goes beyond the annotation without contradicting it.

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 tightly written sentences plus a note: purpose, methodology, and alternative. Every sentence earns its place and there is no redundant or filler content.

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 2-param read-only tool, it clearly conveys what the tool returns (project counts and estimated funding), common category IDs, and an alternative. Minor gaps: how to discover non-common category IDs or a more detailed output shape, but these are not critical.

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 already covers both parameters with descriptions and examples (100% coverage), but the tool description enhances them by listing additional common category IDs (e.g., 30=Cardiovascular, 85=Mental Health) and explaining the agency-based fallback, which gives extra semantic value beyond the schema.

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 states 'Get NIH project counts and estimated funding for a disease/research area across fiscal years', naming a specific verb, resource, and scope. It also distinguishes itself from the sibling nih_projects_by_agency by suggesting that tool for more reliable disease-area counts.

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 gives clear context for use: it retrieves category-based spending across fiscal years. It explicitly names an alternative (nih_projects_by_agency) and when to consider it ('For the most reliable counts by disease area'), but stops short of a full when-not-to-use statement.

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