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

The annotations already declare the tool as read-only, idempotent, and non-destructive, which covers the safety profile. The description adds that the tool returns links to sitemap, docs, contact, and discovery documents, which is useful behavioral context about the output contents. However, it does not describe the response format or any other behavior beyond providing these links, so it offers modest additional value.

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, concise sentence that front-loads the core purpose ('What BL Sign is') and immediately follows with the key contents (links to sitemap, docs, contact, discovery documents). Every word earns its place, and there is no redundant or extraneous information.

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 zero-parameter, read-only tool with annotations already covering safety and idempotence, the description is sufficient. It explains what the tool returns (an explanation and links), and there is no output schema to elaborate on. It does not mention that it requires no input, but the empty schema makes that clear. Overall, it is complete enough for correct 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?

The input schema has zero parameters, and no additional parameter semantics are needed. The baseline of 4 is appropriate because with no parameters to describe, the description does not need to compensate for any schema gaps. The description correctly focuses on the tool's purpose rather than 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 states the tool's purpose: to explain what BL Sign is and provide links to its sitemap, docs, contact, and discovery documents. This distinguishes it from siblings read_page and search_pages, which operate on individual pages or search within the site, making it easy for an agent to understand when to select this tool.

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 does not explicitly state when to use this tool versus the alternatives. While the phrase 'What BL Sign is' implies an informational/overview use case, there is no mention of read_page or search_pages, nor any guidance about when site-level information is more appropriate than page-level reading or searching. Usage context is left to inference.

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