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

With no annotations, the description carries the behavioral burden. It does disclose that titles are discarded, suggesting the output is a count rather than story content, and 'current' implies a live snapshot. However, it does not state the return format, whether network access is required, how errors behave, or that no parameters are needed, leaving transparency incomplete.

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 very short—two terse sentences—and front-loads the core verb and object. Every phrase earns its place; 'Titles discarded' clarifies scope without 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?

For a tool with no output schema and no annotations, the description leaves key context unresolved: whether to call with zero arguments, how optional parameters like 'city' or 'json' relate (if at all) to counting HN stories, and what exact result the agent will receive. The 9-parameter schema makes the description too thin to fully guide invocation, even though the core purpose is clear.

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%, and each of the 9 optional parameters has its own description, so the schema already documents parameter-level meaning. The tool description adds no mapping between these parameters and the HN count behavior, although 'Titles discarded' echoes the feed parameter's phrasing. Baseline 3 is appropriate because high schema coverage means the description need not duplicate parameter docs.

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 opens with a specific verb ('Count') and resource ('current Hacker News front-page stories'), so an agent can clearly grasp what the tool does. It does not explicitly differentiate from siblings, but no sibling name covers this exact HN story-counting purpose. 'Titles discarded' adds a useful scope qualifier, though it is terse.

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?

No guidance is provided about when to use this tool versus alternatives like web-fetch or fetch-status. The description implies a use case but includes no exclusions, preconditions, or references to sibling tools. An agent must infer both selection and invocation behavior from the name and one-line description.

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