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

Despite having robust annotations (readOnlyHint, idempotentHint), the description adds significant behavioral context: data source fan-out, fallback order (GDELT preferred, GNews on rate limit/5xx), USPTO soft-fail due to PatentsView sunset, and parallel execution. This goes well beyond the structured hints.

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 compact yet information-dense. It front-loads with query paraphrases, then methodically covers sources, fallback, parameters, return shape, and alternative tool—every sentence earns its place with no redundancy.

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?

For a 3-parameter tool with no output schema, the description is remarkably complete: it explains the data sources, fallback behaviors, parameter formats, return structure (changes[] grouped by source + total_changes + citation URIs), and provides an alternative tool reference. No critical context 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%, so the baseline is 3. The description enhances parameter understanding by explaining `since` format variants (ISO vs. relative shorthand), providing examples, and adding a usage recommendation ('Use "30d" or "1m" for typical monitoring'). It also adds examples for `value` (ticker or CIK), which, while present in the schema, is reinforced in context.

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 identifies the tool as a 'change feed for a company in the last N days/weeks/months' with specific verbs (e.g., 'What's new', 'latest on', 'updates on') and a defined resource scope (SEC EDGAR, GDELT→GNews, USPTO). It distinguishes itself from sibling tools by emphasizing the parallel fan-out and explicitly contrasting with 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?

It provides explicit when-to-use context via natural language queries and when-not-to-use guidance by stating 'Use entity_profile instead when you want the static profile... regardless of window.' This directly names an alternative, fulfilling the requirement.

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