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

Annotations only cover the safety profile (read-only, non-destructive, closed-world), so the description carries the rest and does so richly: closed target periods are marked 'ended', revenue/diluted-EPS guidance gets an actual-plus-verdict comparison once comparable XBRL facts exist, non-GAAP is never compared to GAAP actuals, and coverage notes distinguish unprocessed documents from sources with no guidance.

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?

Three sentences, front-loaded with the action and sources before the comparison/coverage caveats; no filler. It is dense but each clause carries information an agent needs.

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 usefully characterizes the return shape (ranges, units, basis, fiscal period, provenance, actuals and verdict, coverage notes). It stops short of error or no-coverage edge behavior beyond the coverage-notes hint, but is adequate for a single-parameter read 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 coverage is 100% with a single fully documented ticker parameter (including the MIC:TICKER non-US form), so the schema does the work. The description adds nothing about the parameter, making the baseline 3 correct.

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?

States a specific verb and resource ('Get company guidance') and pins down the two source types (Item 2.02 earnings releases, earnings-call transcripts) plus the ordering and the returned fields (range, unit, GAAP basis, fiscal period, provenance). This clearly separates it from siblings like GetEarningsBrief, GetEarningsCallTranscript, and GetNonGaapBridge.

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?

Gives clear context for when the tool is the right one: it draws guidance only from earnings releases and call transcripts, newest first. It does not name an alternative tool or state exclusions, so the agent still has to infer routing against GetEarningsBrief/GetNonGaapBridge.

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