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

Beyond the readOnlyHint, openWorldHint, and idempotentHint annotations, the description discloses detailed behavioral traits: multi-source fan-out to SEC EDGAR, GDELT→GNews fallback on rate limit or 5xx, and USPTO soft-fail due to PatentsView API sunset. It also explains the parallel nature of the call.

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 but well-structured, starting with natural-language examples, then the core definition, source details, and return format. It is longer than minimal but every sentence contributes useful information; no filler.

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?

With no output schema, the description compensates by specifying the return structure: changes[] grouped by source, total_changes count, and pipeworx:// citation URIs. It also covers multi-source behavior, fallbacks, and date formats, making it self-contained for an agent.

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 description coverage is 100%, providing a baseline of 3. The description adds extra meaning for `since` by detailing ISO date format and relative shorthand with examples, and clarifies `value` accepts ticker or zero-padded CIK. This pushes above baseline.

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 defines the tool as a change feed for a company over a recent window, with concrete example queries. It explicitly contrasts with entity_profile, which returns a static profile, thus distinguishing it from a key sibling. The verbs 'fans out' and 'change feed' convey the action and scope.

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 context (e.g., 'what's new with X', 'latest on Y') and names an alternative: 'Use entity_profile instead when you want the static profile'. This gives the agent 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.