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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds value beyond them by disclosing the breadth of returned data (billing attempts with status and error messages, activity log) and a data-hygiene rule: 'Private customer links are removed.' It stops short of stating not-found/error behavior.

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?

A single dense sentence front-loads the resource and then enumerates payload contents, with no filler. The trailing 'GET /subscription?id=.' fragment is slightly awkward and redundant given the schema, 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?

With no output schema, the description carries the return-value burden and does so well by enumerating nearly every returned section and noting that private customer links are stripped. Missing only error/not-found semantics, which is a minor gap for a single-record getter.

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% and the parameter already documents the crucial distinction between `id` and `internal_id`. The description's 'GET /subscription?id=' only echoes the schema, adding no new semantic detail. Baseline 3 applies when the schema carries the parameter burden.

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 opens with a specific verb+resource ('One subscription with everything Seal knows') and enumerates the exact payload contents (addresses, items, billing attempts, fulfillment orders, invoices, tags, activity log). The singular 'One subscription' implicitly separates it from sealsubscriptions_list_subscriptions, though no sibling is 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?

Usage is only implied: the framing of 'one subscription' with full detail suggests a single-record lookup versus the list tools, and the trailing 'GET /subscription?id=' hints at the access pattern. There is no explicit when-to-use statement, no prerequisites, and no named alternative such as list_subscriptions for bulk retrieval.

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