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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the exact skip rules (weekends, national holidays, the Dec 20–Jan 20 recess) and the caveat that it is only an estimate excluding local holidays and court suspensions.

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?

Two sentences, front-loaded with the core function and legal basis, followed by the accuracy caveat. Every clause earns its place and nothing is repeated from the schema.

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 an output schema present, returns need not be explained, and the annotations cover the safety profile. The description supplies the counting rules and limitation disclosures an agent needs to interpret results correctly, leaving only minor gaps such as how the estimate surfaces in the output.

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 coverage is 100%, so the baseline is 3. The description adds meaning beyond the schema by explaining the counting regime that governs the 'contagem' parameter (business vs calendar days, statutory suspension window) and the legal reference for 'diaDoComeco' not being counted, which the schema only partially conveys.

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?

States a specific verb (estima/calcula) and resource (data final de um prazo processual civil), with the legal grounding (arts. 219, 220 e 224 do CPC). This clearly distinguishes it from every sibling, which are all lookups/validators rather than a deadline calculator.

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 makes the use context clear: computing a procedural deadline in business days or calendar days. It also sets expectations by declaring what it will not cover (local holidays, court-ordered suspensions), which guides correct usage. It does not name an explicit alternative, but no sibling tool competes for this task.

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