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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false. The description adds one genuinely new fact outside those annotations: the call is free (no credit cost), which matters for a metered platform. It does not disclose the shape of the response or whether the entitlement is account-scoped or page-scoped, so it adds only marginal 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?

Two short sentences, front-loaded with the core action and followed by the safety/cost note. 'Changes nothing' partially duplicates readOnlyHint/destructiveHint, so one clause is slightly wasted, but there is no bloat.

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 no parameters, the description is the only place an agent can learn what an 'entitlement' record contains, and it does not say. For a trivial zero-arg read the bar is low, but a single clause naming the fields or scope (e.g. page limits and included features for the current plan) would close the gap.

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 of 4 applies. The description correctly implies no inputs are required.

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 verb (read) and a resource (the plan's entitlement for the website page), so the general purpose is inferable. However, 'what the plan includes' is vague about what is actually returned (limits, quotas, feature flags?) and it never distinguishes this from closely named siblings such as soclo_plan, soclo_wallet, or soclo_host_plan_get. An agent cannot tell from this text alone which plan-reading tool it needs.

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?

There is no statement of when to call this versus soclo_plan, soclo_wallet, or soclo_page_get, and no prerequisites or preconditions are given. The only guidance is an implied 'it is safe/cheap to call', which is coverage of safety, not of selection.

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