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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: the resource-equivalence behavior and the fact that the tool will not pick an account for you when multiple exist, plus 'caller can access' implies permission scoping.

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 sentences, each carrying distinct information: what is returned, why this tool exists alongside the resource, and how to handle multiple accounts. Nothing is redundant with the title.

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?

An output schema exists, so return shape need not be explained, and the description covers the resource equivalence and selection caveat. It stops just short of noting whether results are account-scoped by auth context or ordered, but nothing essential for calling it 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. The description correctly signals a no-argument call by describing a full enumeration with no filtering options.

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 resource (every social account the caller can access) plus its connected platforms, which is exactly what distinguishes it from connect_account or get_team_info. An agent knows this is a read-only enumeration of accounts, not a mutation or a team lookup.

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?

Explicitly tells when to use it: clients that cannot read MCP resources, since it mirrors postey://accounts. It also pre-empts a likely failure mode by stating that when several accounts exist, choosing one is the user's call rather than the tool's. No explicit when-not or named sibling alternative, so not a 5.

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