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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds meaningful context beyond that: the call has no side effects ('without submitting anything'), requires no authentication ('Public'), and states the pricing model explicitly.

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?

Three short sentences, front-loaded with the core action and cost unit, then the public/no-submit facts, then the input-selection rule. No filler and nothing buried.

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 7-parameter tool with no output schema, the description covers the essential pricing semantics and range specification but leaves the interaction between 'intervals'/'language' and the credit cost unexplained, which is central to a quoting tool.

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 57%, and the description usefully clarifies the mutually exclusive date-range inputs ('either from/to or days') and defines 'days' as the most recent n archived days. It says nothing about how 'intervals' or 'language' affect the credit total, even though the schema hints that language changes how many market-days a run may hold.

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 ('Price') and resource ('backtest scope') with the unit defined ('1 credit = 1 market-day'), so an agent knows this computes a cost estimate. It does not explicitly differentiate itself from the sibling backtest_capacity, which likely covers a related capacity/cost question.

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?

'Without submitting anything' implies this is the pre-flight/dry-run call rather than an execution call, which is useful usage context. However, no sibling is named as an alternative and there are no explicit when-not conditions (e.g., when to use backtest_capacity instead).

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