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

Annotations declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds context about what the event contains (narrative, settlements, changes, open items, age/source of figures), which is useful. It doesn't disclose pagination, response size, or any rate limits, but for a read-only retrieval tool this is acceptable.

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 description is a single, information-dense sentence in Polish. It front-loads the core purpose and enumerates the report's contents compactly. It could be slightly more structured, but it earns its place with no filler.

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 read-only retrieval tool with a clear schema and no output schema, the description covers the conceptual content well. However, it doesn't explain the relationship between `eventId` and `quarter` (e.g., which takes precedence) beyond the schema's note, and it doesn't clarify what 'event' means in this domain. The sibling list is large, but the description is enough to distinguish it from most.

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 67%: `eventId` and `quarter` are documented in the schema, while `symbol` is not. The description doesn't add parameter-level detail beyond the schema, but the schema already covers the two most nuanced parameters. The description's mention of 'age and source of each figure' hints at what `quarter` and `eventId` control, but not explicitly.

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 and resource: it presents a quarterly report as an event, summarizing what it says, what it settled, what it changed, what remains open, with age and source for each figure. This is clear and distinct from generic report tools, though it doesn't explicitly name a sibling alternative.

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 implies the tool is for retrieving a quarterly report event with detailed breakdowns, and the schema clarifies that `quarter` can be omitted for the most recent report. However, it doesn't explicitly state when to prefer this over siblings like get_quarterly_kpis or get_earnings_deepdive, nor does it state exclusions.

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