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

Annotations already cover the write/idempotent/non-destructive profile, and the description adds two things they don't: the required "account" scope (auth prerequisite) and "Free" (no credit cost). It stops short of saying what state changes or how to confirm the follow succeeded, but adds real value beyond structured fields.

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 clauses, front-loaded with the action, then prerequisite, then cost. No filler; each fragment carries actionable information.

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 one-parameter mutation with annotations and no output schema, the description covers action, auth scope, and cost. Only the post-call state (does it appear in list_follows immediately?) is unaddressed, a minor omission.

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?

Single parameter with 100% schema coverage; the schema already explains it accepts a slug or podcast_id from find_podcasts. The description adds nothing new about the parameter, so baseline 3 applies.

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?

Clear verb+resource ("Follow a podcast") with an analogy to the UI Follow button, which pins the semantics precisely. The inverse sibling unfollow_podcast makes the direction unambiguous, though it is not named explicitly.

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?

States a prerequisite ("Needs the 'account' scope") and implies a positive precondition implicitly via the button analogy, but gives no when-not guidance or explicit pointer to unfollow_podcast/list_follows as alternatives. Usage context is implied rather than spelled out.

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