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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioral context with the dedup rule ("same-period source mentions are not distinct new earnings") and the saved-vs-all-market scope, but says nothing about ordering, pagination, or behavior when query is empty.

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 short sentences with no filler, and the scope constraint is front-loaded. The second sentence is slightly elliptical ("are not distinct new earnings") but still earns its place as a dedup warning.

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?

An output schema exists, so return-value detail is not needed, and the tool is low complexity with one optional parameter. However, the mismatched name/behavior (companies vs earnings) and the unstated empty-query semantics leave an agent uncertain about how to invoke it without arguments.

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 0% for the single "query" parameter, so the description must carry the meaning, and it does partially by enumerating accepted identifier forms (name, verified ticker, CIK). It omits the fact that query is optional with an empty default and what an empty query returns, leaving a significant gap.

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 says "Find saved earnings by name, verified ticker or CIK," which conveys the lookup inputs and the "saved" scope, but it is mismatched with the tool name list_earnings_companies (it never states that a list of companies is returned). The phrase "not all-market coverage" usefully scopes the resource, yet the core verb+resource pair remains ambiguous.

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?

"not all-market coverage" implies a boundary but names no alternative sibling (get_earnings, list_deals) for full-market or other lookups, so the agent must guess. The dedup note about same-period source mentions is guidance about results, not about when to select this tool.

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