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

Annotations already declare read-only, idempotent, and open-world behavior, but the description adds substantial context: sources (SEC EDGAR, GDELT→GNews fallback, USPTO), failure modes (PatentsView sunset soft-fail), and return format (changes[], total_changes, citation URIs). This goes well beyond the annotations and fully discloses behavior.

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 dense but well-organized: starts with query examples, then summarizes the core function, lists sources and fallbacks, clarifies parameter syntax, and ends with an alternative tool. Every sentence provides necessary information with no filler or repetition.

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 no output schema, the description fully covers return values, parameter formats, source behaviors, and fallback/error conditions. It also gives usage guidance and sibling comparison. The description is complete enough for an agent to select and invoke this tool confidently.

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%, so the baseline is 3. The description enriches semantics by explaining the `since` parameter's accepted formats (ISO date vs relative shorthand) with examples and recommending '30d' or '1m' for typical monitoring. This adds value beyond the schema's plain descriptions.

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's function: a change feed for a company over a recent window, with natural-language examples. It distinguishes itself from siblings by explicitly pointing to entity_profile as an alternative for static profiles, making it unambiguous.

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?

Gives explicit usage context via example queries ('What's new with X') and specifies when to use entity_profile instead. It also details the fan-out and fallback behavior, so an agent knows what to expect and when this tool is appropriate.

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