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

Annotations already declare readOnlyHint=true, signaling a safe read operation. The description adds the capability to filter, sort, and expand relations, and mentions the REST endpoint, but does not disclose behavioral traits like pagination limits, default values, or response structure beyond what the schema provides. This is acceptable but not rich additional context.

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 a single sentence with zero wasted words. It front-loads the core purpose ('List subscriptions') and includes only essential capability hints and the endpoint reference. Ideal conciseness.

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?

The tool is a straightforward list operation with a complete schema and a read-only annotation. The description mentions filtering, sorting, and expansion, which are the main behaviors an agent needs to know. No output schema exists, but the return value (a list of subscriptions) is implied. It is complete enough for agent invocation, though it could mention that the result is a paginated list.

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%, so the schema fully explains all five parameters. The description's mention of 'filtering, sorting, and expansion' maps to the where, sort, and expand parameters, adding a small layer of context but not surpassing the schema's semantics. Baseline 3 is appropriate.

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 states 'List subscriptions' with a specific verb and resource, and adds capability scope ('filtering, sorting, and expansion'). This clearly distinguishes it from sibling tools like get_subscription (single item) and other list_* tools for different resources.

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 description implies the tool is used to list subscriptions, which is clear from the name and resource. It does not explicitly name alternatives (e.g., get_subscription for a single subscription), but the context of sibling tools provides implicit differentiation. No exclusions or when-not-to-use guidance is given, so it falls slightly short of explicit usage guidance.

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