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

Annotations cover the safety profile (non-readOnly, non-destructive, non-idempotent, closed-world), so the bar is lower. The description still adds non-obvious behavior: the one-page-per-account constraint and the fact that this claims a public username, which together explain why it is not repeatable. It does not say what happens if the username is already taken.

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, front-loaded with purpose and precondition, then the style hint and the follow-up workflow. No filler and nothing repeated from the schema.

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?

With no output schema and a 6-param creation tool, the description covers purpose, precondition, key option, and next steps. It omits failure behavior (username collision) and what the call returns, which an agent arguably needs before chaining into add_tile.

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 67%, and the description only addresses `style` (omit for a starter template) while adding genuinely useful routing to list_options for what each look is like. Four of six parameters (layout, preset, template, empty) get no mention in the description, so it neither compensates for the coverage gap nor falls below the baseline for a partially documented schema.

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+resource ('create the user's page') and adds a scope constraint ('one per account') plus the username-claim side effect. An agent can distinguish this from get_page, import_page, and add_tile without opening a schema.

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?

Explicit precondition naming a sibling: 'Do this once, when get_page says there is no page.' It also routes style selection to list_options and tells the agent what to do next ('Then add tiles and publish'), covering both when-to-use and what-follows.

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