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

No annotations are provided, so the description carries full burden. 'VERBATIM as authored' usefully signals no transformation or regeneration, but nothing is said about the return shape, whether it is read-only, or what 'internal' implies for the caller.

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?

A single compact bracket-tagged sentence; nothing is wasted. Slightly cryptic, but structure and front-loading are good.

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 2-param, no-annotation, no-output-schema tool sitting among ~15 coach_* siblings, the description is too thin: no behavior, no param meaning, no routing vs siblings. The verbatim guarantee is the one genuinely useful piece of context.

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% over two params (id required, subject optional). The description never mentions either parameter, and this tool's purpose is returning authored unit content, so the subject filter's meaning and the id's role are undocumented anywhere.

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 (coach) and resource (one unit) and clarifies it returns content verbatim as authored. However, 'unit' is undefined jargon and the description gives no way to distinguish it from the many sibling coach_* tools beyond the vague word 'one'.

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?

No guidance on when to use this instead of coach_next, coach_mastery, coach_recommend, or coach_subjects. The '[WALK · internal]' tag hints at an internal flow but never says when the agent should call it or what precedes/follows it.

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