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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds one important trait: 'Verbatim; never generated', which tells the agent the output is sourced data, not AI-synthesized. However, it does not explicitly state that the operation is read-only, has no side effects, or requires no special auth, leaving some behavioral uncertainty.

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 a single, compact sentence that front-loads the core purpose ('Coach (K-3 tutor) — one subject's whole path') and includes the essential components, default, and a key behavioral note. Every clause earns its place, with no redundant information.

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 simple tool with one optional parameter and no output schema, the description is quite complete. It names the output elements (unit count, tracks, ordered unit briefs) and the default subject. It lacks only minor details like whether the output is a list or object, but the low complexity does not demand much more.

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 schema has only one parameter (subject) with no description, so schema coverage is 0%. The description compensates by explaining that '?subject= selects the path' and specifying a default value ('read'). This adds meaningful context beyond the raw schema, though it does not enumerate possible values or format constraints.

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 clearly states what the tool does: it provides a coach overview for a K-3 tutor subject's whole path, including unit count, tracks, and ordered unit briefs. The phrase 'one subject's whole path' distinguishes it from sibling tools like coach_unit (specific unit) and coach_subjects (list of subjects), making the purpose unambiguous.

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 description gives clear context for when to use this tool: when you need a whole-path overview for a subject. It implies it is the go-to for broad curriculum structure rather than a specific unit, but it does not explicitly name alternative tools or state when not to use it. The context is strong, but exclusions/alternatives are left implicit.

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