Check whether a body is valid JSON. The body is discarded.
| Name | Required | Description | Default |
|---|---|---|---|
| url | No | HTTPS URL to normalize or cite | |
| host | No | Public hostname | |
| json | No | JSON text to validate; discarded after the check | |
| zone | No | IANA timezone name |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It does add one useful behavioral detail: 'The body is discarded,' disclosing that no persistent state is kept. However, it does not disclose the return behavior (success/error, boolean vs details), whether any network call is made (the url parameter hints at this), or any side effects beyond discarding. It is partially transparent but not complete.
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?
Two short sentences with zero filler. The core purpose is front-loaded, and the behavioral note about discarding is placed compactly at the end. Every word 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 is simple, but there is no output schema and no annotations, so the description must explain what the agent can expect back from a validation call — it does not. It also never clarifies what 'body' refers to relative to the schema's four parameters, and the presence of unrelated params (url, host, zone) could mislead an agent. The discarding behavior is noted, but the outcome and invocation focus are left ambiguous.
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 schema already documents each parameter individually. The description adds no parameter meaning beyond the schema; the only added phrase ('The body is discarded') is also present in the json param description. The description does not clarify which of the four params ('url', 'host', 'json', 'zone') is relevant, which is a missed opportunity given several unrelated sibling params appear in the schema.
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 states a specific verb and resource: 'Check whether a body is valid JSON.' This clearly distinguishes the tool from siblings like normalize-url or timezone, which deal with other data types. However, the word 'body' is ambiguous — it could mean the json parameter or an HTTP response body — so it is clear but not perfectly precise.
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 gives no guidance on when to use this tool versus alternatives, and no exclusion criteria. Its usage is implied by the name and purpose ('validate JSON'), but it never explicitly says 'use this when you need to check if a JSON string is valid' or mentions when not to use it. Sibling tools are not referenced.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools target a distinct shape or check, but `citation` and `normalize-url` both return URL host/scheme information, and `timezone`/`utc-time` overlap enough to cause occasional misselection. Overall, tool descriptions clarify the intended purpose in most cases.
All tool names are lowercase and hyphenated, which is a consistent casing convention. The mix of noun-style names like `citation` and verb-object names like `validate-json` is a minor semantic inconsistency but not a confusing one.
With 11 tools, the count is within a reasonable range for a lightweight utility server. Some reference-style helpers like `status-catalog` and `iana-zones` could be consolidated, but the set is not bloated.
The set covers URL, time, phone, JSON, and robots shape checks, but the broad 'shape' theme suggests notable gaps such as email or IP address shape validation and timezone conversion. These omissions are workable but could cause agent dead ends.