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

With no annotations provided, the description carries the transparency burden. It does disclose a behavioral trait: 'Titles discarded' indicates output excludes titles, and 'current' signals fresh data. It does not, however, mention whether the tool makes a network request, whether it is read-only, how failures are handled, or what the exact return format is.

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 redundant wording. The main action is front-loaded, and 'Titles discarded' is a useful secondary note. Every phrase earns its place.

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 and no annotations, yet the description provides no guidance on how to invoke it given the 9 optional, seemingly unrelated parameters. It is unclear whether any parameter is required, which parameter should be passed, or what exactly 'discarded' means for the input. An agent cannot confidently choose and populate the correct invocation from this 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 the baseline is 3 even though the description adds no parameter-level detail. The schema descriptions exist but are broad and seem misaligned with the tool's stated purpose; nothing in the description helps an agent choose among the 9 optional parameters. The description does not compensate for the ambiguity, so it stays at baseline.

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 operation: 'Count current Hacker News front-page stories.' This is a verb + resource combination that is easily distinguishable from the sibling tools, which focus on URL shape checks, validation, or fetching. The additional phrase 'Titles discarded' further clarifies that the tool returns a count, not story titles.

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 intended use is implied: use this tool when the agent needs the number of current Hacker News front-page stories. However, there is no explicit when-not-to-use guidance or mention of alternatives, and the description does not address the 9 optional parameters or whether any input is actually needed.

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