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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered and the description need not restate it. The description does add that results include the program page and award checker links plus a qualitative rating, which is valuable given there is no output schema. It stops short of disclosing the thresholds behind 'great, fair or poor' or how an unrecognized program is handled, so it adds moderate value rather than rich behavioral context.

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?

It front-loads the core purpose ('What a balance of points or miles is worth') and then layers the optional richer computation, which mirrors the required-vs-optional parameter split nicely. It is dense and slightly convoluted in the second half, but no sentence is wasteful.

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 five parameters, two required, and no output schema, the description does enough: it covers the base valuation, the optional award comparison, the rating output, and the returned links. The main residual gap is the absence of any hint about how program identifiers resolve or what the rating cutoffs are, but the fully described schema absorbs the former and the latter is a minor detail.

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, but the description adds real meaning beyond the schema by explaining how cash_price and taxes_and_fees combine to produce the cents-per-point figure — i.e. they represent the same booking priced two ways. That relational context is not obvious from the individual field descriptions, which are written per-field. cash_copay is not discussed in the description, but the schema documents it adequately.

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 uses a specific verb+resource framing: it values a points/miles balance at Points Frog's program value and, when a cash price is supplied, computes cents per point and a great/fair/poor verdict. This is distinguishable from narrow lookup siblings like get_point_value and list_point_values because it clearly describes a calculation, but it never names those siblings explicitly, leaving the agent to infer the boundary.

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?

Usage is implied rather than stated: 'Given the cash price of the same booking (and the award's taxes and fees), also works out the cents per point' tells the agent that supplying cash_price unlocks the richer comparison, which is useful conditional guidance. However, there is no explicit when-to-use/when-not statement, no mention of when to prefer get_point_value or compare_point_programs instead, and no note on what happens if cash_price is omitted.

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