Count URLs, emails, hashtags, mentions and numbers in a text block. Pure CPU, instant.
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"text": "<text>"
},
"name": "entity_count"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | Text to scan |
Changes observed during successful MCP inspections.
Input schema / properties / textAdded value: +{
+ "description": "Text to scan",
+ "type": "string"
+}Input schema / requiredAdded value: +[
+ "text"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full burden. "Pure CPU, instant" usefully discloses that this is a fast, side-effect-free local computation, but it says nothing about the output shape (per-type counts), empty/missing-match behavior, or input limits.
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, the counted resources front-loaded ahead of the performance note. No filler or redundancy.
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 single-parameter, no-output-schema counting utility, the definition covers purpose and cost profile adequately. The only remaining gap is the shape of the returned counts, which the description could have sketched in a clause.
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?
Only one parameter, and the schema documents it at 100% coverage ("Text to scan"). The description reinforces the scope ("a text block") but adds little syntax beyond the schema, which is acceptable for a single-parameter tool.
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?
Names a specific verb (Count) and enumerates exactly what is counted: URLs, emails, hashtags, mentions, numbers, scoped to a text block. An agent can tell this apart from generic text tools. It does not explicitly name the nearest siblings (word_count, word_frequency, extract), so it falls short of a 5.
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?
"Pure CPU, instant" hints at a cheap local operation, but there is no statement of when to choose this over word_count, word_frequency, or extract, and no exclusions. Usage must be inferred from the resource list alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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