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

The annotations only specify destructiveHint: false, and the description adds that the session is a container. However, it does not disclose potential side effects, such as what happens if a session already exists for the period, or whether any other state is created or modified. The description carries some weight beyond annotations but leaves gaps.

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 two short sentences, front-loaded with the primary action, and contains no redundant information. Every word contributes to understanding the tool's purpose.

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 description explains the basic creation action but does not mention the return value (no output schema exists), nor does it connect to related reconciliation workflows. Within its simplicity, it covers the main function, but the lack of output/response details and relationship to sibling tools leaves room for improvement.

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?

The input schema has 100% description coverage for all four parameters, each with a clear description. The tool's description only references 'período específico', which maps to existing schema fields, adding no additional meaning beyond the schema.

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 specific action ('Cria uma nova sessão de conciliação') and the resource ('sessão de conciliação'), and explains its role as a container for comparing transactions and entries. This distinguishes it from sibling tools like reconciliation_import_transactions or reconciliation_execute.

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 that this tool is used to start a reconciliation process for a given period, but it does not explicitly state when to use it versus other reconciliation tools, nor does it provide exclusions or alternative recommendations. The context is clear but not fully elaborated.

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