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

Annotations already declare readOnlyHint and idempotentHint, and the description adds significant behavioral context: fan-out to multiple sources, fallback logic (GDELT preferred, GNews on rate-limit/5xx), and soft-failure of USPTO due to the PatentsView API sunset. It also discloses the return structure including citation URIs, exceeding the annotation coverage.

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 and front-loaded with purpose, followed by source details and alternative direction. While it has many clauses and embedded examples, every sentence contributes distinct information with no fluff. It is slightly longer than necessary but well-structured.

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?

For a tool with no output schema, the description adequately covers return values (changes[], total_changes, citation URIs) and explains multi-source fan-out, fallback behavior, and soft-failure. It also provides parameter formatting and sibling differentiation, making it fully self-contained 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 mostly reiterates what the schema already states for 'since' and 'value', with only minor additions like typical monitoring window suggestions ('30d' or '1m'). These do not significantly deepen parameter understanding beyond the schema.

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 identifies the tool as a 'change feed for a company' with a specific verb and resource, and it lists concrete sources (SEC EDGAR, GDELT→GNews, USPTO). It also explicitly distinguishes itself from sibling 'entity_profile', resolving potential 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 (e.g., natural language queries like 'What's new with X') and an explicit alternative: 'Use entity_profile instead when you want the static profile... regardless of window.' It also offers practical parameter advice like using '30d' or '1m' for typical monitoring.

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