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

Annotations already indicate readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds valuable behavioral details: no pagination, single vs bulk retrieval, and optional accounts grouping. This fully informs the agent about the tool's safety and behavior without contradiction.

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 at 4 sentences, each adding unique value. It front-loads the core action and then provides options and use case. No wasted 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?

Given no output schema, the description mentions returned fields (id, name, type) but could elaborate on the structure of accounts[], though the complexity is low (3 params). It is mostly complete for its purpose.

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?

Input schema has no descriptions (0% coverage). The description compensates by explaining each parameter's effect: supplier_id returns one supplier, supplier_ids enables bulk, and accounts groups results. This adds significant meaning beyond the raw 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 tool lists suppliers with specific fields (id, name, type), supports single retrieval by supplier_id and bulk via supplier_ids, and mentions grouping by accounts. It distinguishes from sibling tools like contasimples_bill or contasimples_category by focusing on suppliers and expense classification.

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 says 'Use para classificar despesas em relatórios' (use to classify expenses in reports), giving a clear usage context. It also mentions bulk support. However, it does not specify when not to use it or provide alternative tools, leaving some room for improvement.

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