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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses important behavioral traits: fan-out to multiple sources, fallback logic (GDELT preferred, GNews when rate-limited or 5xx), PatentsView API sunset behavior, and soft-fail semantics. It also explains the return structure and 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 efficient; every sentence provides context—examples, data sources, fallbacks, parameter formats, return structure, and alternative tool. It is longer than a minimal description but well-structured and front-loaded with usage examples. Slight deduction for length, but no waste.

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?

Given the tool's complexity (multi-source, fallback, soft-fail), the description covers all necessary context: return output (changes[] grouped by source, total_changes, citation URIs), parameter syntax, source behavior, and when to use the sibling entity_profile. Since no output schema exists, the description adequately compensates.

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?

The input schema already thoroughly documents all three parameters with examples (e.g., 'since' accepts ISO date or relative shorthand with recommended '30d' or '1m'). The description adds little beyond providing query examples, so it earns the baseline 3 for high schema coverage without needing to compensate.

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 states a specific verb+resource+scope: 'change feed for a company in the last N days/weeks/months in ONE parallel call' and names the exact sources (SEC EDGAR, GDELT/GNews, USPTO). It clearly distinguishes from the sibling tool entity_profile by contrasting the dynamic change feed with a static profile.

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?

The description provides explicit guidance on when to use this tool ('What's new with X', 'latest on Y', etc.) and gives an explicit alternative: 'Use entity_profile instead when you want the static profile... regardless of window.' It also mentions the one-call efficiency benefit, which conveys when this tool is preferred.

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