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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the description gets a lower bar — and the trailing 'Behavior: read-only' is mostly redundant with them. What it does add beyond structured data is the auth prerequisite (needs PAYWALL_API_KEY) and the shape of the returned record, both of which are genuinely useful.

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?

Three short, front-loaded lines — purpose, disambiguation, behavior — with no filler. The second sentence partially restates the first, and 'Behavior: read-only' duplicates the annotation, so it is not maximally economical, but it is well within a reasonable size for a simple getter.

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 parameters, no output schema, and full annotation coverage, the description supplies everything an agent needs: what it returns, that a PAYWALL_API_KEY is required, and what it is not for. Missing only failure-mode detail (e.g., what happens without a valid key), a minor gap for a zero-arg read.

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 tool takes zero parameters, so the baseline is 4 and there is no parameter semantics to document. The description correctly implies no input is required, and nothing in it misleads about arguments.

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 names a specific verb+resource (get your tenant record) and enumerates the fields it returns (name, slug, key hint). It also explicitly disclaims route management, which cleanly separates it from the paywall_*_route siblings in the tool list.

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?

It gives a positive trigger (use when you want your tenant record) and an explicit exclusion (not for route management), which is more than most definitions offer. It stops short of naming the specific alternative tools (paywall_list_routes, paywall_create_route), so the agent must infer the handoff rather than being routed to it.

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