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

Annotations provide readOnlyHint=true and destructiveHint=false, so the description does not need to restate safety. The description adds that it is paginated and accepts filters with specific date formats and situation values. It does not disclose default page size, response structure, or potential side effects (if any), but given annotations cover the key safety traits, the added behavior is sufficient. No contradiction found.

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 and front-loaded with the main purpose. It provides the key details in a few lines. The use of parenthetical code reference is a minor extra but doesn't bloat it. Every sentence adds value: purpose, pagination, filter details, and use case.

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?

Given the tool has no output schema and limited annotations, the description covers the main aspects: what it lists, pagination, and filter semantics. It even provides a use case (reconciliation with Banco MCP). It does not mention response format or default pagination parameters, but for a list tool with read-only permissions, this is adequate. The sibling tools are many but the description sufficiently distinguishes it as a payables list.

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 schema has 0% description coverage, and the description compensates for the key filter parameter by explaining its JSON structure and accepted values (dataInicial/dataFinal formats, situacao values). It also mentions other filter examples like nomeCliente. However, the other parameters (page, search, account) are not explained beyond their names, which is minimal. Overall, the description adds meaning beyond the schema, especially for the 'filters' parameter.

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 it lists payables ('contas a pagar') and mentions pagination and locality to a PHP script. It clearly distinguishes from sibling tools like tiny_list_receivables and other list tools. However, it uses a specific code reference (contas.pagar.pesquisa.php) which may not be immediately helpful but does not harm clarity.

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 mentions use in reconciliation with the Banco MCP ('Pareia com o Banco MCP na conciliação'), which gives some context. However, it does not explicitly state when to use this tool over alternatives like tiny_list_invoices or tiny_list_receivables, nor does it provide exclusions or conditions. The guidance is implied but not explicit.

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