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

With no annotations, the description carries the full behavioral burden. It usefully discloses the data source (SEC EDGAR) and the 90-day cap, and read-only behavior is strongly implied by 'Lists', but it does not state pagination, rate limits, or what the returned items look like.

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?

Two sentences, front-loaded with the core verb and resource, with the decoding behavior and examples earning their place. No filler, though slightly more could be trimmed.

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 simple two-parameter read tool with no output schema, the description covers purpose, scope, source, and output enrichment. It is nearly complete; only the absence of alternative guidance keeps it from a 5.

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 both parameters are already documented in the schema. The description restates the days window ('last N days, max 90') but adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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 states a specific verb (Lists) and resource (8-K filings), plus the scope (last N days, max 90). It adds value beyond the name by explaining that item codes are decoded to plain English and gives concrete examples. It does not explicitly distinguish itself from the sibling list_filings, so it falls short of a 5.

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?

Usage is implied: an agent can infer it is for recent 8-K events for a given company. However, there is no explicit when-to-use vs. when-not guidance and no mention of alternatives such as list_filings or the need to resolve the company first via resolve_company.

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