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

The description goes well beyond the readOnly/idempotent annotations by disclosing round-robin sampling across sources, windowCoverage field semantics, ceiling truncation behavior, and the difference between recency and relevance ordering. It also states that calls count toward monthly searches, which is important operational context.

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 long and dense, but almost every sentence adds needed behavioral context, especially since there is no output schema. The purpose is front-loaded in the first sentence. Some repetition of 'pure recency digest' and the detailed windowCoverage semantics could be tightened, but the complexity justifies the length.

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 tool with 11 parameters, no output schema, and no required parameters, the description covers what is returned (opportunities plus newSince summary), the sampling and coverage behavior, ceiling truncation, stateless watermark usage, free-tier behavior, and search-count cost. An agent has enough context to call this tool correctly and interpret its response.

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 91%, so the schema already documents most parameters. The description adds meaningful behavior beyond the schema: query presence changes the ordering mode, since enables a stateless watermark pattern, and days filters on ingest freshness rather than posted date. Some parameters (compact, cursor, user_context) are left to the schema, which is acceptable given high coverage.

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 names a specific verb (returns opportunities ingested in last N days), a specific resource (FundingLandscape opportunities), and a clear scope ('what's new since I last checked'). It explicitly differentiates itself from search tools by positioning this as the dedicated recency digest instead of remembering the new_within_days parameter.

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?

It states this is for recurring agent checks and calls out the alternative pattern ('instead of remembering the new_within_days param on a search tool'). It gives concrete guidance: omit query for a pure recency digest, pass since for a stateless watermark, and narrow with query/status/source.

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