List plan feature access

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavioral context beyond that: it explains the available/locked semantic, clarifies this is not a usage quota, and implies features can be gated by plan. This is valuable for interpreting results, though exact response shape is not described.

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?

The description is front-loaded with the core purpose, followed by a concise distinction from quotas, value semantics, and an alternative endpoint. Every sentence carries useful information and there is no filler.

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?

For a simple one-parameter, read-only tool with no output schema, the description covers what the tool returns conceptually, what the values mean, what it does not cover, and when to use it. Nothing an agent needs for correct invocation 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?

Schema description coverage is 100%, and the single parameter profileUuid is documented in the schema as 'Profile uuid parameter.' The description adds no additional parameter-level detail, but with full schema coverage the baseline 3 is appropriate.

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?

Description opens with a specific verb and resource: 'List which plan features the profile can use.' It clearly distinguishes itself as the feature lock matrix rather than a usage quota, and separates from the limits endpoint, so an agent can tell this apart from related billing/limits tools.

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 the agent when not to use it: 'For remaining emails, recipients and AI credits use the limits endpoint instead.' It also gives a concrete use case—checking before building something that cannot be activated, such as an automation on a plan without automation activation—which helps select this tool in planning workflows.

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