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

The annotation readOnlyHint=true already indicates this is a safe read operation. The description adds that it is 'FREE' and lists content areas (endpoints, prices, legal notice), which is useful context. It does not describe the return format or any side effects, but for a simple informational tool with read-only annotation, the description adds reasonable value beyond the annotation.

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, compact sentence that front-loads 'FREE' and then lists the covered topics in a clear, scannable format. Every word adds information; there is no fluff or redundancy. It is appropriately sized for a zero-parameter tool.

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?

Given the tool has no parameters, no output schema, and simple informational nature, the description covers what the tool returns: a description of endpoints, prices, payment details, data source, legal notice, and usage instructions. It is sufficiently complete for an agent to know what to expect. The only minor gap is not stating the output format (e.g., text), but this is not critical for a description tool.

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?

There are zero parameters, so per the rubric the baseline is 4. The description does not need to elaborate on parameters since there are none. It correctly focuses on the content of the description rather than parameter handling.

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 the tool's purpose: describing the API service, including endpoints, prices, payment details, data source, legal notice, and usage instructions. It clearly identifies a specific resource (the service) and the kind of information provided. It distinguishes itself from sibling tools that access data (get_tender, search_tenders) by focusing on service metadata rather than data retrieval.

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 usage by mentioning 'how to use the paid tools' and 'FREE,' suggesting it should be consulted before using paid tools. However, it does not explicitly state when to use this tool versus the siblings, nor does it provide exclusions or alternative guidance. The context is inferable but not explicit.

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