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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds real value by declaring the coverage universe (only 390 US companies) and by explaining that dates may be 'confirmed or estimated' and results appear only 'once out' — semantics an agent could not infer from 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 payload is front-loaded into one dense sentence that leads with the resource and scope before listing fields, and the final sentence gives the one actionable filter. It is somewhat clause-heavy but every clause carries information; no filler sentences.

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 and parameter documentation is complete, so the description need not explain return values, and it correctly focuses on what the data represents (estimates vs. actuals, confirmed vs. estimated). Minor residual gaps — pagination behavior via `limit` and the 'larger companies first' ordering — are covered by the schema rather than the description.

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 schema already documents ranges, defaults, and mutual exclusivity of `month` vs `from`. The description only restates that `symbol` filters to one ticker and that a month or a date range is accepted, adding essentially no syntax or format detail beyond structured fields; baseline 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 names a specific resource and verb ('companies reporting earnings') and enumerates exactly what the tool surfaces: the day, BMO/AMC timing, EPS and revenue estimates, confirmed vs. estimated status, actual vs. consensus, and beat streak. It also states the covered universe (the 390 Portfolio Terminal companies), which lets an agent distinguish it from dividend_calendar and analyze_ticker without opening a schema.

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?

It explains that `symbol` narrows to one ticker and that reporting can be scoped to a month or a date range, which implies usage, but never states when to choose this over sibling tools such as dividend_calendar or analyze_ticker. No exclusions or preconditions are given beyond the schema's note that `from` supersedes `month`.

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