Search open public funding calls

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

Annotations already declare readOnly/idempotent/openWorld, and the description adds genuinely non-obvious behavior: it runs a named Apify Actor on the user's account, costs ~$0.003 per call with a $0.5 per-call cap, and returns results sorted soonest-deadline-first. That cost and billing context is real added value not in the structured fields.

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?

Three compact sentences, front-loaded with the what and where, then the returned fields, then ordering and billing. The field enumeration (title, funder, programme, grant size...) is slightly redundant with the output schema but stays tight.

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 multi-source aggregator with an output schema present, the description covers sources, geography mapping, sort order, forecast inclusion and cost model — everything an agent needs before calling. Return-value detail is correctly delegated to the output schema.

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 every one of the 8 parameters is already documented, including the cost-scaling note on max_items. The description adds no parameter-specific syntax or semantics beyond restating that results carry grant size, deadline and eligibility fields, so the baseline 3 applies.

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?

States a specific verb and resource ('Open and forecast public funding calls') and enumerates the exact sources (Grants.gov, EU Funding & Tenders, UKRI), so an agent immediately knows the scope. It doesn't explicitly distinguish itself from the sibling search_tenders, which is the closest potential overlap.

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?

Usage is implied by the search-and-filter shape and the source enumeration, but there is no explicit 'use this instead of X' guidance against search_tenders or search_gov_updates. Deadlines and forecast inclusion are described, which helps framing, but selection criteria are left to inference.

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