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

Annotations already indicate readOnly, idempotent, non-destructive. Description adds critical behavioral context: fan-out to multiple sources with specific fallback logic (GDELT preferred, GNews on rate-limit, USPTO soft-fail), output structure, and citation URIs. This goes well 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 well-structured with a clear front-load of trigger examples, followed by source details and parameter explanation. It is slightly verbose with the list of examples, but every part is informative. Efficient use of text.

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 no output schema, the description fully explains return values (changes[] grouped by source, total_changes count, pipeworx:// citation URIs). It covers all relevant behavioral aspects (fallback, soft-fail, date formats) for a complex multi-source tool, ensuring the agent can use it 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 covers all parameters with descriptions. The description adds valuable context: relative shorthand patterns ('7d', '30d', '3m', '1y'), typical monitoring window ('30d' or '1m'), and value formats (ticker or CIK). While schema baseline is 3, this extra guidance merits a 4.

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 explicitly defines the tool as a change feed for a company, listing specific trigger phrases ('What's new with X', 'latest on Y') and sources (SEC, GDELT/GNews, USPTO). It clearly distinguishes from the sibling entity_profile tool, making purpose unambiguous.

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?

Provides explicit when-to-use examples and directly states when to use the alternative entity_profile ('Use entity_profile instead when you want the static profile...'), offering clear guidance on tool selection.

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