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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, covering the safety profile. The description adds value by disclosing the exact scope of data returned (price, size, tiers, etc.) and implies no side effects. It doesn't describe error behavior, but for a read-only get-by-id, the annotations plus field list are sufficient.

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, well-structured sentence front-loads the purpose and enumerates the returned fields compactly. No redundant wording or filler; every element earns its place.

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 description lists the key return fields, which compensates for the lack of an output schema. It names the source tools for the id, giving the agent enough context to call it correctly. Missing error-handling or pagination details are minor for a simple read-only get, so it is nearly complete.

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 both parameters (product_id and market) are fully documented in the schema. The description reinforces the origin of product_id (from find_cheapest or search_products), which adds a small semantic nuance beyond the schema, but does not materially extend parameter meaning. 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 clearly states the verb (Get), the resource (a single product by its id), and enumerates the specific fields returned (price, unit price, size, tiers, buy link, price history). It distinguishes itself from siblings like search_products (which searches) and find_cheapest (which finds the cheapest), making its purpose unambiguous.

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?

Explicitly instructs the agent to use the id returned by find_cheapest or search_products, which tells when to use this tool (after obtaining an id) and implicitly when not to (when you don't yet have an id). This is direct usage guidance that reduces ambiguity.

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