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

The description discloses fan-out to three APIs, the GDELT→GNews fallback behavior, USPTO soft-fail due to PatentsView API sunset, and return structure (changes[], total_changes, citation URIs). Annotations already declare read-only/idempotent, so this adds valuable operational context 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 relatively long (~100 words) but dense with behavior and usage. The opening query examples and parameter format repetition slightly overlap with schema, but overall every sentence contributes meaningful context. Could be tightened but is acceptable for the tool's complexity.

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 (multiple sources, fallback logic, no output schema), the description is thorough. It covers return shape, source-specific behavior, API sunset implications, and differentiates from a sibling tool. This provides sufficient context for an agent to invoke correctly.

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 descriptions for all three parameters. The description repeats the `since` format and `value` options (ticker/CIK) without adding new parameter semantics beyond the schema. The only slight addition is recommending '30d' or '1m' for typical monitoring.

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's purpose with user-facing query examples ('What's new with X') and defines it as a 'change feed for a company in the last N days/weeks/months'. It names the specific sources (SEC EDGAR, GDELT/GNews, USPTO) and distinguishes itself from 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 provides concrete use-case triggers and explicitly advises when to use an alternative: 'Use entity_profile instead when you want the static profile...'. It also explains operational fallbacks (GDELT preferred, GNews when rate-limited) and the soft-fail condition for USPTO.

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