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

Annotations already indicate readOnly, openWorld, idempotent, and non-destructive, but the description adds substantial context: it fans out to SEC EDGAR, GDELT→GNews with a specific fallback condition, and notes USPTO soft-fails after a sunset. It also discloses the return shape (changes[], total_changes, citation URIs), which annotations do not cover.

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 dense yet well-organized, front-loading the purpose and then logically covering sources, parameter syntax, return structure, and an alternative tool. Every sentence contributes useful information without redundancy or fluff.

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, parameter flexibility, and no output schema), the description thoroughly covers inputs, outputs, error behavior (soft-fail), and how to differentiate from a sibling tool. It leaves no critical gaps 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%, so the baseline is 3. The description adds value by explaining the since parameter's accepted formats (ISO date and relative shorthand) and recommending '30d' or '1m', which helps agents select a reasonable window. It also reinforces value as ticker or CIK, though the schema already states this.

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 over a time window, answering queries like 'What's new with X'. It specifies the resource (company changes), the action (retrieve feed), and distinguishes itself from the sibling tool entity_profile by clarifying it provides the static profile instead.

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 guidance through example questions and states a direct alternative: 'Use entity_profile instead when you want the static profile...'. It also describes fallback behavior across sources, which informs usage under rate limits or API unavailability.

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