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

Annotations only declare readOnlyHint=false, idempotentHint=true, destructiveHint=false and openWorldHint=true; the description adds real substance beyond that. It discloses partial-update semantics ('any subset'), that levels are replaced as a whole list, that a level cannot be removed while a page sits at its depth, that a renamed level retains its fields, and that a new slug rewrites every page address inside it — a non-obvious cascade. Only the return/response behavior and permission requirements are left unstated.

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?

It is short and dense, with no filler, and the level/slug caveats are worth their words. But it is written in clipped fragments ('On one site of the account, named in site.'), which makes the leading sentence awkward to parse and delays a clear statement of the action. Tightening into a proper opening clause would improve it without adding length.

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 mutation tool with seven parameters, nested objects and no output schema, the description covers the risky parts well: partial updates, whole-list level replacement, the blocking condition for removing a level, and the URL cascade from a slug change. Missing pieces are minor for this complexity — no mention of validation failures or what the call returns.

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 coverage is 57%, and the description compensates for some gaps: it explains the site parameter's role, the subset/partial-update semantics, and the consequence of changing slug, plus the levels/fields interplay ('a renamed level keeps its fields'). However, name and description parameters get no clarification at all, and the fields payload is documented almost entirely in the schema. Baseline-plus is appropriate.

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 enumerates exactly what can be changed on a collection (name, levels, slug, description, per-level fields) and scopes the operation to a single site. The verb is only implied by the tool name and the fragments ('A collection's name, levels, slug... any subset'), but an agent can still distinguish this from create_collection or delete_collection. No sibling is named, so it falls short of a 5.

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?

There is no explicit when-to-use guidance: nothing says to call get_collection first, when to prefer update_collection over delete_collection plus create_collection, or what preconditions exist. The only contextual hint is the level-removal constraint, which is a behavioral rule rather than usage direction. The agent must infer the usage from the name alone.

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