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

Annotations already indicate readOnly, openWorld, idempotent, non-destructive. The description adds substantial context: parallel fan-out to multiple sources, fallback mechanism, soft-fail for USPTO, and return structure (changes grouped by source, total_changes, citation URIs). This goes beyond 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 a single dense paragraph that front-loads the purpose. Every sentence adds value, but it could benefit from slightly more structure (e.g., bullets for sources). Still, it is appropriately sized and not verbose.

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?

Despite no output schema, the description explains the return structure (changes grouped by source, total_changes, citation URIs). It covers all major aspects: sources, fallback, parameter formats, and distinction from entity_profile. Context is complete for the tool's complexity.

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%, but the description adds value: explains since accepts ISO or relative shorthand, recommends defaults (30d/1m), clarifies type is limited to 'company', and value can be ticker or CIK. This enriches parameter understanding.

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 explicitly states the tool provides a 'change feed for a company in the last N days/weeks/months' and lists example queries. It details the sources (SEC EDGAR, GDELT→GNews, USPTO) and distinguishes from entity_profile, making the purpose very clear.

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 gives explicit guidance on when to use ('what's new' queries) and when to use entity_profile instead for static profiles. It also explains fallback behavior (GDELT preferred, GNews on rate limit), which helps the agent decide.

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