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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it completely fails. The description says 'number discarded' which is nonsensical given the schema. Several parameter descriptions mention 'discarded after the check' (ref, city, json, query), suggesting side effects or ephemeral behavior, but the main description does not explain what the tool does, what it returns, or what side effects occur. The description contradicts the schema's apparent purpose.

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 short (5 words), which is concise, but it is under-specified to the point of being useless. It does not front-load any actionable information. The schema is large and well-structured, but the description fails to provide the orienting summary 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?

This is a 10-parameter tool with no output schema and no annotations. The description provides zero context about what the tool does, what it returns, or how the parameters relate. The sibling list includes many similar validation tools (browser-url-ok, fetch-status, file-path-ok, validate-json, etc.), and this description does nothing to distinguish acre-ha from them. The tool is completely inadequate for an agent to select or invoke correctly.

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, but the description itself is actively misleading. The tool name and description suggest a unit conversion, while the schema describes 10 unrelated string parameters for checking URLs, files, JSON, timezones, etc. The parameter descriptions in the schema are individually clear, but the tool-level description does not tie them together, and the 'Acres to hectares' framing makes the parameters even more confusing.

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 'Acres to hectares, number discarded' is a tautology that restates the tool name and provides no meaningful information about what the tool actually does. The input schema shows 10 unrelated string parameters (ref, url, city, feed, host, json, path, zone, query, website), which contradicts the acres-to-hectares framing entirely. An agent cannot determine what this tool does from this description.

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?

There is no guidance on when to use this tool versus any of the 30 sibling tools. The description does not mention any context, prerequisites, or alternative tools. The schema parameters suggest it might be a multi-purpose validation/checking tool, but the description gives no indication of when it should be invoked.

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