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

readOnlyHint=true already covers the safety profile, so the description's job is to add context — and it does: it explains each returned field's meaning and discloses the plan gate ('`available` says whether the plan runs rules (Pro and higher)'), which is exactly the kind of prerequisite an agent can't get from annotations. It stops short of saying what unset or default values look like.

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?

A single dense sentence that front-loads the four field names with inline parenthetical definitions, followed by the plan-availability note — no filler. It is slightly hard to scan as one long clause chain, and the missing leading verb makes the very first fragment read like documentation rather than an operation.

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 shape, and it does so field by field, plus the plan-availability flag. The remaining gap is minor: it doesn't state the value types or what an unconfigured rule 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?

The tool takes zero parameters, so there are no parameter semantics to document; the baseline of 4 applies. The description instead spends its space explaining the response fields, which is the right allocation for a no-arg getter.

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 reads as a definition of the returned resource ('The workspace's four rules: ...') rather than a verb phrase, but combined with the annotated title 'Get the rules' the operation is unambiguous. It clearly differentiates the content (rules config) from data returned by siblings like get_workspace or get_reply_times, though it never names set_rules as its counterpart.

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?

Usage is only implied: an agent infers this is the read path for the same rules that set_rules writes. There is no explicit when-to-use statement, no mention of set_rules as the mutation alternative, and no statement about who should call it or what a caller does with the result.

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