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

With no annotations provided, the description carries the full burden of disclosing behavior. It only notes that titles are discarded, which is a minor detail. It does not explain how the nine parameters are used (or ignored), what happens with invalid inputs, or the format of the count result. The parameter descriptions in the schema suggest they are discarded after checks, but the tool description does not confirm this or elaborate, leaving significant behavioral gaps.

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 extremely concise—two short sentences with no fluff. It is front-loaded with the core purpose. However, conciseness is not the same as completeness; while it is structurally efficient, it omits critical information that an agent needs.

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 9 parameters, none required, and no output schema, the description is severely incomplete. It fails to explain how to invoke the tool, what the parameters are for, whether they are all ignored, or what the returned count looks like. An agent cannot confidently call this tool based on the current description alone.

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 coverage is 100%, so each parameter has a description. However, these descriptions are generic (e.g., 'Git ref name; discarded after the shape check') and do not relate to counting Hacker News stories. The tool description adds no clarification on how these parameters influence the count or if they are simply ignored. The baseline of 3 for high coverage is lowered because the parameter descriptions are misleading and do not help an agent understand the tool's actual function.

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 a specific verb and resource: 'Count current Hacker News front-page stories.' It distinguishes from sibling count tools by subject matter, though it doesn't explicitly mention alternatives. The phrase 'Titles discarded' adds a small behavioral note. The main issue is the disconnect between this purpose and the generic parameter list, which weakens clarity about how the tool actually works.

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 no guidance on when to use this tool versus alternatives like 'memory-key-count' or 'web-fetch'. It doesn't mention prerequisites, limitations, or scenarios where it would be inappropriate. There is no explicit or implied context for selecting this tool over others.

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