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

Annotations already cover safety (readOnlyHint, idempotentHint, non-destructive), and the description adds behavioral content beyond that: the tool exposes links to sitemap, docs, contact, and discovery documents. This tells the agent what kind of output to expect without contradicting the annotations. It stops short of describing output structure, but for a zero-parameter informational tool this is adequate.

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 sentence that front-loads the core purpose and then lists the key content types. Every phrase adds value and there is no redundant repetition of the title or annotations. It is as concise as possible while being informative.

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 simple, zero-parameter, read-only tool, the description covers the essential context: what the site is and what resources the tool links to. The lack of an output schema is partially compensated by the described content (sitemap, docs, contact, discovery documents). Exact return formatting is not specified, but an agent can reasonably invoke this tool for site orientation.

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?

The tool has zero parameters, so there are no parameter semantics for the description to clarify. Per the baseline for tools with no parameters, this dimension carries no additional burden. The description appropriately says nothing about inputs.

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 identifies the resource as information about Black Label Operator and its discovery documents, sitemap, docs, and contact. While it lacks an explicit action verb like 'returns' or 'provides', the purpose is unambiguous. It is distinguishable from siblings read_page and search_pages by its site-level scope, though this differentiation is implied 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 description implies this tool is for orientation: understanding what the site is and finding its key documents. However, it does not explicitly say when to use site_info versus read_page or search_pages, nor does it mention excluded cases. The usage context is inferable but not stated.

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