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

Annotations provide basic information (not read-only, not destructive). The description adds that the tool creates a record and specifies required fields, but does not disclose additional behavioral details such as authentication needs, error responses, idempotency, or side effects beyond creation. Given the annotations, the description adds modest context.

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 concise: two sentences front-loading the action and then detailing the main parameter. Every sentence adds essential information without redundancy. No unnecessary words.

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 creation tool with no output schema, the description covers input in detail but omits return value information (e.g., whether it returns the created payable ID). It references external documentation but does not summarize error handling or idempotency (idempotentHint is false). The description is adequate for input but incomplete for full agent understanding.

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 has 2 parameters with 0% description coverage. The description explains the 'data' parameter in detail (JSON string with required fields and references to other tools) but does not mention the 'account' parameter. This partial coverage adds value for the main parameter but leaves one parameter undocumented.

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 creates a payable account ('Lança (cria) uma conta a pagar') and references the specific API endpoint (IncluirContaPagar). It distinguishes from siblings like omie_create_receivable and omie_create_customer by explicitly naming the resource type, though it does not directly contrast with them.

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 usage: when creating a payable. It references helper tools like omie_list_customers and omie_list_checking_accounts for prerequisite IDs, but does not explicitly state when not to use it or name alternatives (e.g., omie_update_payable for modifications). Guidance is implicit rather than explicit.

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