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

Annotations declare readOnlyHint/idempotentHint, but the description goes far beyond by detailing fan-out to SEC EDGAR, GDELT→GNews fallback (with rate-limit/5xx conditions), and USPTO soft-fail after sunset. It also describes return structure and citation URIs, adding substantial behavioral context not present in annotations.

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: example queries first, then mechanism, parameters, output, and alternative. Every sentence covers a distinct aspect with no filler. The length is justified by the tool's multi-source complexity.

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 and multi-source fan-out, the description covers all necessary context: input formats, source behaviors, fallbacks, output shape (changes[] + total_changes + citations), and alternative tool. It is complete for an agent to decide when to invoke and what to expect.

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 baseline is 3. The description adds useful guidance beyond the schema: explains ISO vs relative shorthand for `since`, recommends '30d' or '1m', and clarifies that `type` only supports 'company'. This extra meaning justifies a 4.

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 clear example queries and defines a specific verb+resource: 'change feed for a company in the last N days/weeks/months in ONE parallel call.' It explicitly distinguishes from entity_profile, which covers static profile material, making the purpose unambiguous.

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 usage context ('What's new with X' / 'latest on Y') and an explicit alternative: 'Use entity_profile instead when you want the static profile.' It also gives parameter usage tips for `since`, such as 'Use 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.