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

No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing beyond the conceptual math: no return format, no units for rates (percent vs. decimal), no mention of how inflation/volatility are applied, and no note that it is a pure read-only computation. The 'no further contributions' framing is the one useful behavioral hint.

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?

A single front-loaded sentence with no waste; the em-dash clause efficiently explains the milestone. It is appropriately sized, though the brevity contributes to the parameter gaps noted elsewhere.

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 10-parameter financial computation with zero schema descriptions, no annotations, and no output schema, the description is far too thin. An agent knows what the tool conceptually computes but not the units, the role of several optional parameters, or the shape of what comes back.

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 0% across 10 parameters, so the description is the only place meaning could be added — and it adds none. Key ambiguities (are expected_return_rate, inflation_rate, and safe_withdrawal_rate percentages or decimals? what does portfolio_volatility do to the result? why monthly_savings exists in a 'no further contributions' calculation?) are left entirely unresolved.

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 gives a specific verb ('Compute') and resource ('Coast FIRE milestone') and defines the concept precisely: capital that compounds to a retirement target with no further contributions. It is clear, though it never distinguishes itself from the sibling calculate_fire_target, so an agent must infer which FIRE variant to call.

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?

There is no statement of when to use this tool versus calculate_fire_target or project_wealth_plan, no prerequisites, and no exclusions. The definition of Coast FIRE implies a use case but the description provides no routing guidance.

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