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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorld=true, so safety is covered. The description adds genuine behavioral context beyond that: it returns 'every' tier (complete, unpaginated result), clarifies which benefits are included (those shown in the tier editor), and discloses the auth requirement ('Cotlet API key with access to this app').

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?

Four short sentences with little waste; the purpose leads. Slight redundancy between 'Your membership tiers with name, description and benefits' and 'Returns every tier on your Patreon page,' and the 'Patreon:' prefix is low-value, but overall it is tight.

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 zero-parameter, read-only tool with no output schema, the description covers what comes back (tier fields plus benefits), the scope (all tiers), how to use the tier_id downstream, and the auth prerequisite. Little an agent needs 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?

The tool takes zero parameters, so the baseline of 4 applies. There is nothing for the description to add or compensate for on the parameter front.

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?

States a specific verb+resource (list the membership tiers on the user's Patreon page) and enumerates the returned fields (name, description, benefits). It's clear this is a read of tier definitions, distinct from write siblings like update_tier or message_tier, though it doesn't name an alternative 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?

'Use the tier_id of each item in the other endpoints' tells the agent how the output feeds other calls, which is useful context. But it gives no when-to-use or when-not-to-use guidance against siblings and no exclusions, leaving usage implied.

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