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, the description carries the full disclosure burden. It does disclose a meaningful side effect ('The body is discarded'), implying the operation is non-mutating and stateless. However, it does not say what happens for invalid JSON (error vs false), what output the agent should expect, or whether the url/host/zone parameters influence behavior.
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 and the core action front-loaded. The second sentence earns its place by disclosing disposal behavior. Slightly stronger wording would use 'json' instead of 'body' to align with the schema.
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 4 parameters, no required fields, no output schema, and no annotations, the description is incomplete. It explains only a single action loosely, gives no clue why url, host, and zone exist, and does not state the return or error contract an agent needs to act on the result.
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. The description adds no parameter-level meaning beyond the schema, and worse, it calls the input 'body' while the schema calls it 'json', and the unrelated url/host/zone descriptions do not connect to JSON validation. The description fails to resolve which parameter is actually used.
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 names a specific verb ('check') and resource ('a body') and clearly states the tool validates JSON. However, 'body' is ambiguous next to the schema's only relevant parameter, 'json', and the three unrelated parameters (url, host, zone) obscure what is actually being validated. It does not distinguish itself from sibling tools, whose names appear unrelated ('normalize', 'cite', 'timeout', 'sleep').
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 given about when to use this tool vs alternatives, what prerequisites exist, or what inputs are expected. The presence of unrelated parameters with no explanation leaves the agent guessing which parameter combination constitutes the 'body'.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.