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

The description goes beyond the readOnlyHint annotation by explaining the effectiveTier vs planTier distinction and why they may differ, which is a subtle behavioral nuance. It reinforces that no modifications are possible, aligning with the read-only nature.

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 generally concise and well-structured, with the main purpose first, followed by the effectiveTier clarification, alternative tool guidance, and read-only note. Slight redundancy in the read-only sentence, but it does not detract significantly.

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 tool with no parameters and no output schema, the description covers all necessary aspects: purpose, key fields, usage distinction, and operational constraints. It is self-contained and answers likely agent questions about when and how to use it.

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 schema has no parameters, so there is nothing to elaborate. The description adds the prerequisite 'Requires organization context,' which is helpful for agents to know before calling. This context is not reflected in the schema, so the description adds value.

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 clearly states the tool's purpose: 'Get the organization's subscription' and enumerates the specific details it retrieves (plan, status, seat usage, scheduled changes). It distinguishes itself from the sibling tool get_trial, providing a precise scope.

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?

Explicit usage guidance is given: 'Use this for the plan in force; while a trial is running use get_trial.' It also clarifies that modifications are not possible via MCP, telling agents that this is a read-only operation and that changes must be done in the web app.

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