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

Even though annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, the description adds valuable behavioral context: 'It does not create checkout' and 'Its result already renders the exact product card and image.' It also explains what the tool returns (availability, price, disclosures, checkout eligibility), which complements rather than contradicts the annotations.

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 four sentences long and heavy with capitalization, but every sentence carries a distinct operational instruction: the confirmation precondition, the sibling fallback, the exactly-once constraint, the media exclusion, and the return semantics. It is dense rather than bloated, though it could be slightly tightened without losing value.

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 tool with four enum parameters and many siblings, the description covers all decision points: when to call, what to do if inputs are incomplete, how many times to call, what result to expect, and what not to call afterward. An output schema exists, so return-value details are not needed. The definition is complete for correct agent invocation.

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 rich per-parameter explanations such as 'never infer it' and 'never default to Propane or Natural Gas.' The description lists the four parameters and reinforces the global precondition, but it does not add meaning beyond what the schema already provides, so the baseline of 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 starts with a specific verb and resource: 'Resolve an exact Homebridge fire-pit configuration against the live Shopify catalog.' It clearly distinguishes this tool from siblings by explicitly naming qualify_homebridge_fire_pit and the media tools it should not be confused with, leaving no ambiguity about what this tool does.

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 gives explicit when-to-use and when-not-to-use guidance: only after the buyer has confirmed all four selections, and if any selection is missing or ambiguous, call qualify_homebridge_fire_pit. It also states to call exactly once and never follow with the media tools unless the buyer asks, making the routing decision crystal clear.

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