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

With no annotations, the description must carry the behavioral burden. It discloses the data source (IRS Form 990 e-filings) and price, but does not mention limitations (e.g., only health organizations? data freshness, error handling, read-only nature). It adds value but lacks depth.

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 sentences plus a price note, front-loaded with the core action. No wasted words; every sentence adds value.

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 one-parameter tool with no output schema, the description covers purpose, parameter, and source. However, it leaves ambiguity about whether it only covers health organizations and does not describe return format. Adequate but not fully comprehensive.

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% and the schema already describes 'ein' as 'IRS Employer Identification Number (EIN)'. The description adds context that the EIN is for a 'Nonprofit health organization' and that results are filing history, but this is marginal 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 the tool provides 'Form 990 filing history by EIN' and specifies it answers questions about revenues, expenses, and trends. It distinguishes itself from sibling tools like irs990_org_search and irs990_officers_search by focusing on filing history for a specific EIN.

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 when you have an EIN and need filing history, and mentions the data source. However, it does not explicitly state when not to use this tool or suggest alternatives, though the context of sibling tools makes it clear.

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