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

Beyond annotations (readOnly, idempotent, openWorld, non-destructive), the description reveals critical behavioral details: multi-source fan-out, fallback from GDELT to GNews on rate-limiting or 5xx, and the PatentsView API sunset causing a soft-fail until reactivated. This informs users about potential gaps and source prioritization, which annotations alone do not convey.

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 longer than average but information-dense, covering purpose, sources, fallback behavior, parameter formats, return structure, and an alternative tool. It is front-loaded with user intents and avoids filler. Minor deduction for a single dense paragraph that could benefit from clearer sentence separation, but overall every sentence 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 the tool's complexity (multiple sources, fallback logic, data window), the description provides all necessary context: what it returns (structured changes[] grouped by source, total_changes, citation URIs), how to specify the window, and how it differs from entity_profile. Even without an output schema, an agent can invoke it correctly and understand expected results.

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?

Input schema already covers all three parameters at 100% coverage. The description adds extra semantic value by explaining `since` accepts both ISO dates and relative shorthand with examples, and even suggests typical monitoring values. This goes beyond the schema's basic descriptions while complementing them.

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: a change feed for a company in a specified time window, fanning out to SEC EDGAR, news, and USPTO. It explicitly distinguishes itself from the sibling tool entity_profile by directing users to that tool for static profiles, avoiding ambiguity.

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 when-to-use guidance through example queries like "What's new with X" and "updates on Acme," and gives an exclusive alternative: 'Use entity_profile instead when you want the static profile.' It also advises typical monitoring values for the `since` parameter ('Use 30d or 1m'), which helps agents select appropriate inputs.

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