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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and non-open-world behavior, so the safety profile is covered. The description adds the useful clarification that it does not book or charge, but it does not describe the return format or what kind of guidance it supplies.

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 two short sentences with no filler, front-loading the topic and then adding a clarifying limitation. It is concise but arguably under-specified rather than optimally sized for a tool with no output schema.

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 parameters and no output schema, the description should explain what the tool actually provides and when to use it. 'How to start a Block 0 brief' is not self-explanatory, and the description leaves an agent unsure what invoking it will return.

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?

The tool has zero parameters, so there is no parameter semantics burden on the description. Baseline 4 is appropriate when no parameters exist.

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 says 'How to start a Block 0 brief,' which is a vague guide phrase rather than a specific verb+resource. It does not clarify what the tool actually returns or how it differs from sibling tools like get_source_of_truth or list_products.

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 implied use case is learning how to start a Block 0 brief, and the note that it 'does not book or charge' rules out a transactional purpose. However, there is no explicit when-to-use, when-not, or alternative tool guidance.

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