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

The readOnlyHint annotation already establishes this is a safe read. The description adds only the raw HTTP route (GET /stores/{id}), which conveys no behavior beyond what the annotation and name already imply — no auth requirements, error semantics for a missing id, or pagination/sideload 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?

Two very short sentences, zero filler, with the operation and its scope front-loaded and the endpoint appended as supporting detail.

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 should ideally say what a store object contains or what the include sideloading yields. For a simple id-based lookup with full schema coverage and a readOnly annotation, the definition is adequate but leaves the response shape entirely unspecified.

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%: both store_id and the optional include parameter are documented in the schema itself, including the JSON:API include format and example. The description adds nothing beyond the schema, so the baseline 3 applies.

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 a single store by id'), and 'single' implicitly distinguishes it from the sibling lemonsqueezy_list_stores. It stops short of naming that sibling explicitly, so the differentiation is inferable rather than stated.

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 tool's purpose implies its usage (fetch one store when you already have an id), but there is no explicit when-to-use statement, no mention of when to prefer lemonsqueezy_list_stores, and no preconditions. Guidance is implied only.

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