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

Annotations already declare readOnly, openWorld, idempotent, nondestructive. The description adds valuable behavioral details: parallel fetch, source fallback logic, supported 'since' formats (ISO date and relative shorthand with examples), and return structure (grouped changes, total count, citation URIs). No contradictions.

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 strictly necessary, but every sentence serves a purpose—examples, function, sources, fallback, alternative tool. It is front-loaded with queries and well-structured. Slight redundancy in the source enumeration could be trimmed, but overall it earns its length.

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 3 required parameters and no output schema, the description covers all essential aspects: return format (grouped changes, total count, URIs), source behaviors and fallbacks, supported date formats, and clear differentiation from entity_profile. It is complete for an agent to use 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 description coverage is 100%, but the description enriches it further: it explains that 'since' accepts ISO dates or relative strings and suggests default values (e.g., '30d' or '1m'), and clarifies that 'value' can be a ticker or zero-padded CIK. This adds meaning 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 begins with example queries, then clearly states the tool's function: 'change feed for a company in the last N days/weeks/months in ONE parallel call.' It lists specific data sources (SEC EDGAR, GDELT→GNews, USPTO) and explicitly distinguishes from the sibling tool entity_profile, making purpose unmistakable.

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 guidance: 'Use entity_profile instead when you want the static profile ... regardless of window.' It also explains fallback behavior for news (GDELT preferred, GNews on rate limit/5xx) and notes USPTO's soft-failure condition. This clearly tells the agent when to use this tool and when not to.

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