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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context: it ranks by net-of-tax yield, explains that FD interest is fully taxable, and affects ranking via tax_slab_pct. It also states the output format (Top 5, gross & net amount). This goes beyond the annotations and clarifies the computation logic.

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 structured into a one-line purpose, Args, and Returns, making it scannable. The purpose is front-loaded. The Args section is necessary given the schema gap, so it earns its place. Slightly verbose but justified; no filler.

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?

Despite no output schema, the description clearly specifies the return: top 5 FDs with gross and net amounts. It covers the tax logic and the senior-citizen rate nuance. It does not mention any prerequisites or edge cases (e.g., minimum amount), but for a read-only ranking tool, this is sufficient. The description is complete enough for an agent to invoke it correctly.

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 bears full responsibility for parameter documentation. The Args section explains each parameter with units, examples ('1.5 for 18 months'), valid values (5/10/20/30), and the meaning of is_senior_citizen. This is exemplary compensation for the missing 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 a specific verb ('Rank'), a specific resource ('Indian Fixed Deposits'), and the ranking criterion ('net-of-tax yield'). This distinguishes it from siblings like calculate_fd_maturity, which presumably handles a single FD, and compare_products, which may be generic. The purpose is unambiguous and actionable.

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 explains what the tool does but does not explicitly contrast it with alternatives. It does not state 'Use this when comparing multiple FDs' or 'For a single FD calculation, use calculate_fd_maturity instead.' The context implies ranking across FDs, but the exclusion is not spelled out. Without that, an agent might confuse it with calculate_fd_maturity.

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