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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral details beyond that: 'newest first' ordering and the return envelope '{data, total, limit, offset}', both of which help an agent interpret results and paginate.

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, no filler. The first sentence states the action and includes concrete examples; the second covers filters and the return envelope. Every clause carries useful information and the main behavior is front-loaded.

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?

With no output schema, the description compensates by stating the return envelope. It also covers ordering, filter options, and pagination hints via 'total' and 'limit+offset' in the schema. For a read-only list endpoint with fully documented parameters, nothing essential is missing.

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%, so the baseline is 3. The description adds value by giving the example item codes and their meanings (2.02 results of operations, etc.) and by summarizing the filter dimensions, helping clarify the 'item' parameter beyond the schema's bare pattern.

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 a specific verb and resource: 'List SEC 8-K corporate events' and adds classification by official item code. The examples (2.02, 5.02, 1.01, 7.01) and the sibling names (insider trades, IPO registrations, schema) make it easy to distinguish this tool from alternatives.

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 clear context on what the tool is for and explicitly lists the filtering dimensions (item code, CIK, since-date), which tells an agent when this tool fits an 8-K look-up task. It doesn't explicitly name sibling tools or call out when not to use it, so it falls short of a 5 but is still clearly usable.

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