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

Annotations already declare readOnly/idempotent/non-destructive, so the description earns credit for adding specifics beyond them: explicitly no purchase, no private file download, no paid query, plus the per-call endpoint note for hosted APIs. It does not cover errors, auth, or rate limits, which keeps it below a 5.

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 tight sentences, front-loaded with the core action and only mildly compressed in phrasing ('checkout route'). Very little waste, though the second sentence is a negative list that could be terser.

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 does partially enumerate the returned data (version, requirements, review, checkout route), which is helpful. However, for a tool with two schema parameters and zero parameter documentation, the agent still lacks enough to supply inputs confidently.

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 0% across two parameters, so the description must carry the burden, but it says nothing about product_id (the pattern '^product_[a-f0-9]{32}$' is only in the schema) or what agent_key is for. 'Exact version' hints at scope but does not explain any parameter.

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 ('Read one current public product') and enumerates what is returned: exact version, requirements, review and checkout route. It is clear on its own, but does not name or contrast with the similarly named siblings such as speedbot_exchange_read or speedbot_read.

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 clause 'Reading never buys, downloads private files or starts a paid query' sets a clear boundary on when this tool is appropriate versus purchase/download flows, and 'Hosted APIs use their own per-call endpoint' gives a routing cue. It stops short of naming the alternative tools an agent should use for buying or paid queries.

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