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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so an agent knows this is a safe offline computation; the description does not contradict that. Beyond the safety profile it adds units ('in rupees', 'in years'), which is useful, but says nothing about return format or edge cases (e.g., zero/negative growth). With annotations carrying the safety burden, a 3 is appropriate.

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 tool's purpose is front-loaded in the first sentence, followed by a compact Args block. No wasted prose. The Args list partially restates schema titles, which is mildly redundant, but the units justify including it.

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?

There is no output schema, so the description should ideally state what is returned (a percentage vs. a decimal ratio) and handle edge cases, but it stops at explaining inputs. For a simple three-parameter calculator the definition is workable, but the return-value gap is real.

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%, so the description carries the full burden, and it does so well: all three parameters are defined with meaning and units (initial investment in rupees, final value in rupees, holding period in years). This goes beyond the bare schema titles ('Initial Value', 'Years'). A 4 rather than 5 because ordering/format constraints of the parameters are not discussed.

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 and resource: 'Calculate the Compound Annual Growth Rate (CAGR) of an investment.' An agent immediately knows this is a computation tool. It does not, however, distinguish itself from the many sibling calculators (calculate_emi, calculate_sip, calculate_fd_maturity), so a 5 is not warranted.

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?

No guidance on when to choose CAGR over the sibling calculators (SIP, EMI, FD maturity), and no prerequisites or input constraints. The only implied usage is the formula itself. This is pure 'what', with no 'when'.

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