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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavioral context by specifying that it shows financial information over time and calculates trends for assets, grants, and revenue. It also mentions Form 990 or 990-PF, giving additional insight not captured by annotations, though it does not disclose potential limitations like data availability gaps.

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 two sentences long, front-loaded with the primary purpose, and includes supplementary detail about trends and form types without redundancy. Every sentence contributes 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?

Given the tool has an output schema (not shown) and good annotations, the description is reasonably complete. It explains what data is retrieved, the types of forms covered, and the trend calculation. It could be slightly more explicit about prerequisites (e.g., foundation EIN) but the schema already covers that. Overall adequate.

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 covers both parameters (ein and years) with full detail, so description need not add parameter-level meaning. The description's reference to 'over time' and 'trends' implicitly relates to the 'years' parameter, but adds no new semantics beyond the schema. Thus baseline 3 is appropriate.

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 retrieves IRS 990 filing data and calculates financial trends for a foundation. It specifies the resource (IRS 990 filings) and the action (retrieve/show trends), distinguishing it from sibling tools that focus on other aspects like grants or funder profiles.

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 for getting financial trends for a foundation, but does not explicitly state when to use this tool versus alternatives like get_funder_stats or search_funders. It provides context (e.g., 'over time', 'year-over-year trends') but lacks direct comparison or exclusion statements.

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