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

Building on the readOnlyHint, openWorldHint, idempotentHint, and destructiveHint annotations, the description adds substantial behavioral detail: fan-out to SEC, GDELT→GNews fallback, USPTO soft-fail due to API sunset, and rate-limit fallback logic. This far exceeds what annotations alone convey.

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 not bloated. It front-loads with natural-language triggers, then uses compact semicolon-separated clauses to convey source list, fallback logic, date format, return shape, and the alternative tool. Every sentence carries useful information, though a slightly shorter form would be possible.

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 the lack of an output schema, the description explicitly states the return structure: structured changes[] grouped by source, total_changes count, and pipeworx:// citation URIs. It also covers edge cases like GDELT rate-limiting and USPTO soft-fail, making the tool's behavior fully specified.

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?

The input schema covers all three parameters with descriptions, so the baseline is 3. The description goes further by giving concrete formats for `since` (ISO or relative shorthand), examples for `value` (ticker or zero-padded CIK), and clarifying `type` only supports 'company'. This enriches but doesn't merely repeat 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 opens with multiple natural-language phrasings and clearly identifies the tool as a change feed for a company over a time window, executed in one parallel call. It also distinguishes itself from sibling entity_profile by explicitly contrasting time-windowed changes against static profiles.

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 gives an explicit alternative: 'Use entity_profile instead when you want the static profile... regardless of window.' It also recommends typical `since` values ('30d' or '1m'). It doesn't address all possible sibling tools, but the primary ambiguity is resolved.

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