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

Beyond the annotations (readOnlyHint, idempotentHint, etc.), the description adds substantial behavioral details: it fans out to multiple sources (SEC, GDELT→GNews fallback, USPTO), explains fallback logic and soft-fail conditions, and specifies return structure (grouped changes, count, 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 a single paragraph but packs essential information: example queries, core functionality, data sources, parameter guidance, return format, and sibling tool recommendation. No redundant sentences; every part earns its place.

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 no output schema, the description adequately covers return structure (changes[], total_changes, citation URIs). It explains all parameters and source behavior. Minor omission: no explicit mention of maximum window or pagination, but the tool's purpose (recent changes) makes these non-critical.

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 baseline is 3. The description adds practical meaning: explains that `since` accepts ISO date or relative shorthand and recommends '30d' or '1m'; notes that `type` only supports 'company' for now; clarifies that `value` can be ticker or zero-padded CIK. This is useful context 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 clearly states the tool's function: 'change feed for a company in the last N days/weeks/months in ONE parallel call'. It also distinguishes from the sibling tool entity_profile by directing users to use entity_profile for static profiles. This meets the criteria of a specific verb+resource and sibling differentiation.

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 example user queries and explicitly advises when to use a sibling tool ('Use entity_profile instead when you want the static profile...'). It also explains the fan-out behavior and parameter recommendations (e.g., 'Use "30d" or "1m" for typical monitoring'). However, it could mention when not to use this tool in favor of other siblings like recent_alerts, but overall guidance is clear.

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