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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior. The description adds the returned data components, but does not disclose behavior for missing events, partial data, or error conditions, so it adds only moderate context beyond annotations and the output schema.

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 compact sentences with no wasted wording. The content summary is front-loaded, and the lone parameter clarification is appended efficiently.

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?

The output schema covers return values and annotations cover safety, so the description needn't repeat those. However, it omits usage guidance and leaves ticker/fiscal_year semantics unspecified, which are meaningful gaps for a three-required-parameter lookup tool.

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 0%, and the description clarifies only fiscal_period ('FY or Q1..Q4'). It says nothing about ticker formatting or fiscal_year semantics, leaving two required parameters dependent on name and type alone.

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 the resource ('Earnings event') and enumerates the specific contents it returns: 8-K acceptance timestamp, as-reported figures, and derived realized price reaction. This distinguishes it from siblings like get_fundamentals or get_filing_metadata, though the verb is implied rather than stated as 'Retrieve'.

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 no guidance on when to use this tool versus alternatives, nor any exclusions or prerequisites. An agent must infer usage from the tool name and sibling names alone.

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