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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint, and openWorldHint. The description adds valuable behavioral context: it fans out to multiple sources (SEC EDGAR, GDELT→GNews fallback, USPTO), explains the fallback logic, and notes the PatentsView API sunset. No contradiction with annotations, but could mention rate limits or response size.

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 fairly long but well-structured: example queries first, then tool behavior, then parameter details, then return format. It avoids tautology and earns its sentences, though some phrases like 'in ONE parallel call' could be omitted without loss.

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 having no output schema, the description clearly states the return format ('structured changes[] grouped by source + total_changes count + pipeworx:// citation URIs'). It covers fallback behavior, parameter usage, and a sibling reference. For a 3-parameter tool with moderate complexity, this is complete and sufficient.

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%, yet the description goes beyond: for 'since' it clarifies ISO and relative formats with examples, for 'type' it confirms only 'company' is supported, and for 'value' it explains ticker or CIK input. This adds significant meaning beyond the schema 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 query examples ('What's new with X', 'latest on Y') and clearly states the verb+resource: 'change feed for a company in the last N days/weeks/months in ONE parallel call.' It lists the data sources and distinguishes itself from sibling entity_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 explicitly advises 'Use entity_profile instead when you want the static profile', providing an alternative for a different use case. It also gives a best-practice recommendation for the 'since' parameter ('Use "30d" or "1m" for typical monitoring'). However, it lacks explicit 'when not to use' guidance beyond the one sibling reference.

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