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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive. The description adds substantial behavior beyond annotations: parallel fan-out to EDGAR, GDELT→GNews fallback (with failure conditions), USPTO soft-fail due to PatentsView API sunset, and the specific return shape (changes[] grouped by source, total_changes, pipeworx:// citation URIs). No contradiction.

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 every clause earns its place: intent phrases, fan-out behavior, fallback logic, date formats, return structure, and alternative tool reference. It is long but not repetitive or padded; front-loading the intent phrases helps agents recognize applicability.

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 having no output schema, the description covers return format, source behavior, parameter syntax, and an explicit alternative. For a multi-source fan-out tool, this is complete and self-sufficient guidance.

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% with all three parameters described. The description adds practical guidance beyond schema: relative shorthand examples ('7d', '30d', '3m', '1y'), a typical value for monitoring ('30d' or '1m'), and clarifies value can be ticker or CIK. This earns one point above the 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 opens with concrete user-intent phrases ('What's new with X', 'latest on Y'), then states a specific verb+resource: 'change feed for a company in the last N days/weeks/months in ONE parallel call.' It clearly distinguishes from siblings by naming entity_profile as an alternative for 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?

Provides explicit when-to-use via intent examples and gives a clear exclusion: 'Use entity_profile instead when you want the static profile... regardless of window.' The description also clarifies the window semantics with 'since' formats and typical usage ('30d' or '1m').

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