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

With no annotations, the description carries the burden of disclosing behavior. It states the tool 'Returns claimable directory listings filtered by city and/or trade,' which implies a read-only listing operation. However, it does not disclose potential side effects, authentication needs, or limitations such as pagination or claimability criteria.

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 concise and front-loaded, with the primary action and resource in the first sentence. The second sentence adds practical usage guidance. No wasted words.

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 tool has no output schema or annotations, so the description should explain what it returns. It does say 'Returns claimable directory listings filtered by city and/or trade,' which covers the core behavior. It lacks return field details but is otherwise complete for a simple list tool, especially with siblings indicating related actions.

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 the baseline is 3. The description only summarizes the schema's existing filter behavior ('filtered by city and/or trade') without adding new parameter details, formats, or constraints beyond what the schema already provides.

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 uses a specific verb and resource: 'List free dofollow backlink opportunities for Canadian businesses.' It clearly distinguishes from siblings by focusing on free, dofollow, claimable directory listings filtered by city/trade, whereas siblings like check_backlink_status or claim_listing involve status checks or claiming.

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 provides an explicit trigger example: 'Use this when a user asks "where can I get a free dofollow backlink for my Canadian client" or similar.' It gives clear context for when to use, though it does not explicitly state when not to use or name alternative tools.

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