get_subscription_by_id

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description's '[READ]' merely restates that. The REST path (GET /api/subscriptions/by-id/:userId) adds a little context about the underlying resource, but nothing about permissions, 404 behavior, or rate limits.

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 lines, front-loaded with the purpose. The bracketed HTTP verb/path is somewhat redundant with the annotations but costs little.

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?

A simple single-parameter read tool whose safety profile is covered by annotations and whose parameter is fully described in the schema. However, with no output schema, the description says nothing about what is returned (subscription object, link, status), leaving a small but real 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?

Schema coverage is 100% and the single userId parameter is fully documented in the schema. The description reinforces that the identifier is a User ID (not a subscription ID), which is mildly useful, but adds no format or constraint detail beyond the schema. Baseline 3.

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 and resource (get subscription) plus the lookup key (User ID), which distinguishes it from siblings like get_subscription_by_short_uuid_protected and get_subscription_by_username. It does not explicitly name those alternatives, but the key difference is inferable.

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?

No when-to-use guidance, no prerequisites, and no mention of when to prefer this over get_subscriptions or the username/short-uuid variants. The agent must infer selection purely from the key type.

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