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

Annotations only declare readOnlyHint=true, so the description carries most of the burden and delivers: it discloses the return structure (id, name, description, children), the handsOff flag semantics including inheritance to descendants, the immutability of protected features, and the revision value that update_features consumes. It stops short of auth, rate limit, or pagination behavior.

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?

Four short sentences, each carrying distinct payload: return shape, protection semantics, featureId scoping, and the update_features dependency. The scoping and structure information is front-loaded with no filler.

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?

There is no output schema, so the description must explain the return value itself — and it does, enumerating the tree's fields and the handsOff/revision semantics. For a two-parameter read tool with readOnlyHint, nothing needed to call it correctly is missing.

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 description's featureId guidance ('read just that feature and the features under it') essentially restates the schema text for that parameter. projectId is only implied by 'a project's features' and adds no syntax or format detail, so the baseline of 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?

States a specific verb and resource ('Get a project's features') plus the shape of the result ('compact tree'), which is more than the name alone conveys. It also implicitly separates itself from the mutating sibling by noting update_features depends on the returned revision.

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?

Gives a concrete usage branch: pass featureId to read just that feature and its descendants. It also names the downstream consumer (update_features needs the revision) and the constraint that hands-off features cannot be changed, but it never states an explicit when-not or a fully alternative tool choice.

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