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

With no annotations provided, the description carries the full behavioral burden and discloses several non-obvious traits: only published paths are fetchable, nothing is generated on demand, an unknown slug 'simply has no path,' and the whole ordered sequence is returned at once. It stops short of specifying the exact not-found representation (empty list vs. error), which keeps it from a 5.

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 core purpose is front-loaded in the first sentence, and each paragraph earns its place: definition/scope, usage flow, and behavioral constraints. The second paragraph defining a learning path is helpful for sibling discrimination but slightly verbose for a one-parameter read tool.

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 single-parameter tool with no output schema, the description covers return semantics (ordered steps, each with a diagram slug), the sibling workflow (search → fetch path → get_diagram), and edge cases (still generating, unpublished, unknown slug). It could be more explicit about the top-level return structure, but nothing critical is missing for correct invocation.

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 100% and the slug parameter is already well documented with examples of how to source it (query result or URL segment). The description reinforces this by pointing to search_learning_paths results and known slugs, but it adds no genuinely new information beyond the schema, so the baseline 3 applies.

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 first sentence states a specific verb and resource: 'Fetch one Vectree learning path: its ordered steps, each naming the diagram that step teaches.' It clearly distinguishes this fetch-one-path tool from siblings like search_learning_paths, get_diagram, and get_collection, and the term 'one' is reinforced by 'Only published paths can be fetched.'

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 when-to-use context: 'Use it after search_learning_paths, or whenever you already know a path slug.' It also explains how the output feeds the next step via get_diagram and warns to skip steps marked 'still generating.' It does not explicitly state when not to use it versus get_collection or list_collections, so exclusions are missing.

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