GET /bills (Bill)

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the tool is safe. The description adds behavioral context about the two pagination models and the deprecation timeline, which is valuable beyond annotations.

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 with three sentences: purpose first, then array parameter handling, then a critical warning. No unnecessary words, front-loaded effectively.

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?

With 8 optional parameters and no output schema, the description covers pagination behavior and parameter formatting. The schema already describes each parameter fully, so the description adequately complements it. Missing details about filter parameters are not needed since schema covers them.

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 100%, so the baseline is 3. The description adds a note about array parameters accepting comma-separated values but does not significantly enhance meaning beyond the schema descriptions.

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 'Listagem paginada de Despesas' (Paginated listing of Expenses), specifying the verb (list) and resource (bills/expenses). It distinguishes from sibling tools like 'list_bill_categories' which list categories, not bills.

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 provides explicit guidance on pagination: it warns that the limit parameter is mandatory for the new pagination model and that the old model will be deprecated. However, it does not mention when to use this tool over alternatives like 'list_charges' or 'list_sales'.

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