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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is fully covered. The description adds essentially nothing beyond that: no indication of whether results reflect granted vs. requested vs. available scopes, or how stale they may be. It restates the resource without new behavioral context.

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 a single short sentence with no padding, which suits a zero-argument getter. However, it is a noun phrase rather than a front-loaded statement of what the tool does, and 'tiers' is undefined, so brevity comes at the cost of clarity.

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, the description carries the burden of explaining the return value, and it does not — the shape of the tiers/scopes result, whether it includes pending requests, and its relation to request_scopes are all unstated. For a no-param read tool this is thin even though the call itself is trivial.

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 there is nothing for the description to disambiguate; the schema is empty and closed. Baseline 4 applies since no parameter semantics are needed.

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 fragment names the resource it exposes (tiers and scopes held by this connection), so an agent can infer it is a read of granted permissions. But it lacks a verb and never says 'list' or 'returns', and 'tiers' is ambiguous next to siblings like list_plans or billing_status. The purpose is recognizable but not stated as an action.

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?

No guidance on when to call this versus related siblings such as request_scopes, get_account_summary, or list_connections. The only hint is the phrase 'this connection', which implies a current-connection scope but never states prerequisites or exclusions.

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