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

Annotations already declare destructiveHint=true, but the description adds extensive context: it 'CANNOT be undone', 'writes the cap-table of record', 'persists the SAFE conversions + ownership snapshots', and advises to 'confirm with the user first'. This goes well beyond the annotation, disclosing the irreversible and consequential nature of the operation.

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 three sentences long, front-loaded with the tool's core action, and every sentence adds essential information: what it does, how to interpret user intent, and the warning about irreversibility. No redundant wording.

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 destructive, irreversible mutation tool, the description gives sufficient context: the exact workflow, the permanent impact, the user-confirmation requirement, and the alternative preview option. Since an output schema exists, return values don't need elaboration. This is complete for the tool's complexity.

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 only 33% (just 'UUID value wrapper' for companyId and roundId). The description does not explain any parameter meanings, such as newMoneyRaise, preMoneyValuation, carryForwardUnwired, or targetOptionPoolPct. While the parameter names are somewhat self-explanatory, the description fails to compensate for the low schema coverage.

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 clearly states the tool's function with a specific verb and resource: 'CloseCapTableRound PERMANENTLY closes the round' and outlines the exact actions (runs the calc engine, persists SAFE conversions + ownership snapshots, flips the round to CLOSED). It distinguishes itself from the sibling PreviewCloseCapTableRound by explicitly noting the difference between closing and estimating.

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 explicitly defines when to use this tool: 'This is the action for "close the round", "make it permanent", or "finalize the round"'. It also provides a clear exclusion and alternative: 'To only estimate the outcome without closing, use PreviewCloseCapTableRound'. This is strong usage guidance.

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