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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, but the description adds substantial behavioral context: parallel fan-out to SEC EDGAR, GDELT→GNews fallback (with rate-limit/5xx condition), USPTO PatentsView sunset causing soft-fails, and the return shape (changes[] + total_changes + citation URIs). No contradiction.

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?

Despite its length, every sentence carries information: query examples, source details, fallback logic, parameter syntax, return format, and an alternative tool. It is front-loaded with example queries and states the core function immediately, with no filler.

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?

The description covers purpose, usage, data sources, failure modes, parameter syntax, return structure, and alternatives—fully sufficient for a complex multi-source tool with no output schema. Nothing critical is missing.

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% with thorough descriptions for all three parameters (e.g., 'since' already documents ISO/relative formats and typical use). The tool description does not add meaningful parameter semantics beyond the schema, so baseline 3 is appropriate.

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 provides a 'change feed for a company in the last N days/weeks/months in ONE parallel call,' with specific verbs and resources. It distinguishes itself from sibling entity_profile by contrasting dynamic changes vs static profile, making the purpose unmistakable.

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 usage examples ('what's new with X', 'updates on Acme') and provides a direct alternative: 'Use entity_profile instead when you want the static profile... regardless of window.' This is clear when-to-use guidance with an explicit alternative.

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