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

Despite annotations declaring readOnly/openWorld/idempotent, the description adds meaningful behavioral detail: it documents fallback source behavior under rate limiting, the PatentsView API sunset soft-fail, and the exact return shape (changes[], total_changes, citation URIs). No contradiction with annotations.

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, using lists and semicolons to pack source details, parameter formats, and return structure into a single paragraph. Every sentence adds new operational information, though it's on the longer side for a quick scan.

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?

With no output schema, the description fully specifies the return contract (grouped changes, count, URIs) and explains the tool's limitations and fallback behavior. It also provides parameter usage examples, making it a self-contained guide for a complex multi-source tool.

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?

All three parameters are already described in the schema (100% coverage), but the description enriches meaning by explaining 'since' formats with examples (ISO vs relative) and clarifying that 'value' accepts either ticker or CIK. This goes beyond the schema's basic 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 opens with concrete user intents and explicitly states it returns a change feed for a company within a time window in one parallel call. It also names the sibling entity_profile as the alternative for static profiles, distinguishing it clearly.

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 explicitly contrasts with entity_profile ('Use entity_profile instead when you want the static profile...') and tells users the query intent, while also describing the fallback chains (GDELT→GNews, USPTO soft-fail). This gives clear guidance on 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.