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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that - answers are withheld and time/pass mark are included - but does not say whether the exam is persisted, whether repeated calls yield the same exam, or how the withheld answers are later checked.

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?

One compact sentence that front-loads the resource and then lists the salient exam attributes; no filler. It is a sentence fragment with no verb, which slightly hurts scannability but wastes nothing.

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 no output schema, the description carries the burden of describing returns, and it does name the main components (question count, topic spread, time allowed, pass mark, no answers). It still leaves open whether question bodies and identifiers are included in the response and how the resulting exam is later graded, which matters for a mock-exam workflow.

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% and both parameters are documented inline, including the lang enum default and a level id example, so the description need not carry parameter meaning. Its phrase 'of a level' only echoes the already-documented level parameter, adding nothing new.

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 specifies the resource concretely: a mock exam for a level, composed of the level's question count distributed evenly across topics, plus time allowance and pass mark. The composition is clear, but it never differentiates itself from siblings like practice_section or get_questions, and the action verb ('start') appears only in the name.

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 explicit when-to-use guidance, no prerequisites, and no named alternative. An agent must infer from the word 'mock exam' that this is for exam simulation rather than drilling or practice, and must guess how it relates to grade_exam or practice_section.

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