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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the core method (4% rule or custom withdrawal rate), which is meaningful, but it does not explain how current_savings and monthly_investment affect the result, what the output represents, or any assumptions such as inflation or real returns.

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 that front-load the purpose, then list the required and optional parameters. Every sentence contributes operational value and there is no redundant wording.

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 calculator with 5 parameters and no output schema, the description is adequate for selecting the tool and knowing the main inputs. However, it does not state the return format, whether the result is a single target amount, or how optional inputs like current_savings and monthly_investment alter the calculation, which leaves some ambiguity for an agent with no output schema to rely on.

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 parameters are already well documented in the schema. The description adds value beyond the schema by clearly grouping required versus optional parameters and warning the agent to use the exact English field names, which is useful given the Portuguese-language description.

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 a specific verb and resource: it calculates the amount you need to accumulate to live off investment income, using the 4% rule or a custom withdrawal rate. It is clear and distinct in intent, but it does not name or distinguish itself from closely related siblings such as calculate_retirement, calculate_first_million, or can_i_quit_job.

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 when to use the tool: when the user asks about financial independence based on expenses and a withdrawal rate. It also gives operational guidance by listing required and optional parameters and stressing the exact English parameter names. However, it provides no explicit when-not-to-use guidance or alternatives among the many sibling financial calculators.

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