get_subscription_plan

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

Description goes well beyond the annotations: it discloses server-side auth injection, rate-limit throttling/retry behavior, the exact return format (HTTP status + JSON body), and maps specific non-2xx statuses to likely causes. This is rich behavioral context that annotations alone do not provide, with no contradiction.

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 structured with clear labeled sections (Behavior, Returns, Use when) and is front-loaded with the key verb and resource. Each sentence adds distinct value, and nothing is redundant or wasted.

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 single-parameter read-only lookup with no output schema, the description is complete: it covers what is returned, error behavior, auth, throttling, and appropriate usage. No critical information an agent would need to call it correctly 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% with the parameter described as 'Subscription plan Id'. The description repeats the id in prose but adds no new semantic depth beyond what the schema already provides. Baseline 3 applies given complete schema coverage.

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 a specific verb ('Get subscription plan') and resource ('subscription plan specified by the provided subscription plan id'), and explicitly names the sibling tool get_list_subscription_plans to disambiguate. An agent can immediately understand what this tool does and how it differs from the plural list variant.

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?

The 'Use when' section explicitly states it is safe for speculative lookups and reporting, and explicitly says not for changing anything, pointing to the write tool. It mentions the related Subscription plans tool get_list_subscription_plans, though it does not deeply contrast when to choose list vs single-get. Still, the usage context and exclusion are clear.

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